Patchwork [v3,4/5] Copy string_view tests from libstdc++

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Submitter Simon Marchi
Date April 7, 2018, 1:26 p.m.
Message ID <20180407132629.3787-4-simon.marchi@polymtl.ca>
Download mbox | patch
Permalink /patch/26636/
State New
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Simon Marchi - April 7, 2018, 1:26 p.m.
This patch copies the string_view tests from the gcc repository (commit
02a4441f002c).

  ${gcc}/libstdc++-v3/testsuite/21_strings/basic_string_view ->
    ${binutils-gdb}/gdb/unittests/basic_string_view

The local modifications are done in the following patch, so that it's
easier to review them.

gdb/ChangeLog:

	* unittests/basic_string_view/capacity/1.cc: New file.
	* unittests/basic_string_view/capacity/empty_neg.cc: New file.
	* unittests/basic_string_view/cons/char/1.cc: New file.
	* unittests/basic_string_view/cons/char/2.cc: New file.
	* unittests/basic_string_view/cons/char/3.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/1.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/2.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/3.cc: New file.
	* unittests/basic_string_view/element_access/char/1.cc: New file.
	* unittests/basic_string_view/element_access/char/2.cc: New file.
	* unittests/basic_string_view/element_access/char/empty.cc: New file.
	* unittests/basic_string_view/element_access/char/front_back.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/1.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/2.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/empty.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/front_back.cc: New file.
	* unittests/basic_string_view/include.cc: New file.
	* unittests/basic_string_view/inserters/char/1.cc: New file.
	* unittests/basic_string_view/inserters/char/2.cc: New file.
	* unittests/basic_string_view/inserters/char/3.cc: New file.
	* unittests/basic_string_view/inserters/pod/10081-out.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/1.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/2.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/3.cc: New file.
	* unittests/basic_string_view/literals/types.cc: New file.
	* unittests/basic_string_view/literals/values.cc: New file.
	* unittests/basic_string_view/modifiers/remove_prefix/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_suffix/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc: New file.
	* unittests/basic_string_view/modifiers/swap/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/swap/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/compare/char/1.cc: New file.
	* unittests/basic_string_view/operations/compare/char/13650.cc: New file.
	* unittests/basic_string_view/operations/compare/char/2.cc: New file.
	* unittests/basic_string_view/operations/compare/char/70483.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/13650.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/copy/char/1.cc: New file.
	* unittests/basic_string_view/operations/copy/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/data/char/1.cc: New file.
	* unittests/basic_string_view/operations/data/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/find/char/1.cc: New file.
	* unittests/basic_string_view/operations/find/char/2.cc: New file.
	* unittests/basic_string_view/operations/find/char/3.cc: New file.
	* unittests/basic_string_view/operations/find/char/4.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/3.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/4.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/1.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/2.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/3.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/3.cc: New file.
	* unittests/basic_string_view/operations/string_conversion/1.cc: New file.
	* unittests/basic_string_view/operations/substr/char/1.cc: New file.
	* unittests/basic_string_view/operations/substr/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operators/char/2.cc: New file.
	* unittests/basic_string_view/operators/wchar_t/2.cc: New file.
	* unittests/basic_string_view/range_access/char/1.cc: New file.
	* unittests/basic_string_view/range_access/wchar_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc: New file.
	* unittests/basic_string_view/requirements/typedefs.cc: New file.
	* unittests/basic_string_view/typedefs.cc: New file.
	* unittests/basic_string_view/types/1.cc: New file.
---
 gdb/unittests/basic_string_view/capacity/1.cc      | 162 +++++++++
 .../basic_string_view/capacity/empty_neg.cc        |  28 ++
 gdb/unittests/basic_string_view/cons/char/1.cc     |  68 ++++
 gdb/unittests/basic_string_view/cons/char/2.cc     |  47 +++
 gdb/unittests/basic_string_view/cons/char/3.cc     |  39 +++
 gdb/unittests/basic_string_view/cons/wchar_t/1.cc  |  68 ++++
 gdb/unittests/basic_string_view/cons/wchar_t/2.cc  |  45 +++
 gdb/unittests/basic_string_view/cons/wchar_t/3.cc  |  38 +++
 .../basic_string_view/element_access/char/1.cc     |  70 ++++
 .../basic_string_view/element_access/char/2.cc     |  30 ++
 .../basic_string_view/element_access/char/empty.cc |  38 +++
 .../element_access/char/front_back.cc              |  42 +++
 .../basic_string_view/element_access/wchar_t/1.cc  |  71 ++++
 .../basic_string_view/element_access/wchar_t/2.cc  |  32 ++
 .../element_access/wchar_t/empty.cc                |  38 +++
 .../element_access/wchar_t/front_back.cc           |  42 +++
 gdb/unittests/basic_string_view/include.cc         |  25 ++
 .../basic_string_view/inserters/char/1.cc          |  65 ++++
 .../basic_string_view/inserters/char/2.cc          |  93 ++++++
 .../basic_string_view/inserters/char/3.cc          |  54 +++
 .../basic_string_view/inserters/pod/10081-out.cc   |  75 +++++
 .../basic_string_view/inserters/wchar_t/1.cc       |  70 ++++
 .../basic_string_view/inserters/wchar_t/2.cc       |  91 +++++
 .../basic_string_view/inserters/wchar_t/3.cc       |  53 +++
 gdb/unittests/basic_string_view/literals/types.cc  |  45 +++
 gdb/unittests/basic_string_view/literals/values.cc |  72 ++++
 .../modifiers/remove_prefix/char/1.cc              |  61 ++++
 .../modifiers/remove_prefix/wchar_t/1.cc           |  61 ++++
 .../modifiers/remove_suffix/char/1.cc              |  61 ++++
 .../modifiers/remove_suffix/wchar_t/1.cc           |  61 ++++
 .../basic_string_view/modifiers/swap/char/1.cc     |  35 ++
 .../basic_string_view/modifiers/swap/wchar_t/1.cc  |  35 ++
 .../basic_string_view/operations/compare/char/1.cc | 132 ++++++++
 .../operations/compare/char/13650.cc               |  49 +++
 .../basic_string_view/operations/compare/char/2.cc |  30 ++
 .../operations/compare/char/70483.cc               |  89 +++++
 .../operations/compare/wchar_t/1.cc                | 133 ++++++++
 .../operations/compare/wchar_t/13650.cc            |  49 +++
 .../operations/compare/wchar_t/2.cc                |  30 ++
 .../basic_string_view/operations/copy/char/1.cc    |  45 +++
 .../basic_string_view/operations/copy/wchar_t/1.cc |  46 +++
 .../basic_string_view/operations/data/char/1.cc    |  43 +++
 .../basic_string_view/operations/data/wchar_t/1.cc |  43 +++
 .../basic_string_view/operations/find/char/1.cc    | 164 +++++++++
 .../basic_string_view/operations/find/char/2.cc    | 161 +++++++++
 .../basic_string_view/operations/find/char/3.cc    | 161 +++++++++
 .../basic_string_view/operations/find/char/4.cc    |  44 +++
 .../basic_string_view/operations/find/wchar_t/1.cc | 163 +++++++++
 .../basic_string_view/operations/find/wchar_t/2.cc | 161 +++++++++
 .../basic_string_view/operations/find/wchar_t/3.cc | 161 +++++++++
 .../basic_string_view/operations/find/wchar_t/4.cc |  44 +++
 .../basic_string_view/operations/rfind/char/1.cc   |  94 ++++++
 .../basic_string_view/operations/rfind/char/2.cc   |  52 +++
 .../basic_string_view/operations/rfind/char/3.cc   |  66 ++++
 .../operations/rfind/wchar_t/1.cc                  |  94 ++++++
 .../operations/rfind/wchar_t/2.cc                  |  52 +++
 .../operations/rfind/wchar_t/3.cc                  |  66 ++++
 .../operations/string_conversion/1.cc              |  51 +++
 .../basic_string_view/operations/substr/char/1.cc  |  79 +++++
 .../operations/substr/wchar_t/1.cc                 |  79 +++++
 .../basic_string_view/operators/char/2.cc          | 367 +++++++++++++++++++++
 .../basic_string_view/operators/wchar_t/2.cc       | 367 +++++++++++++++++++++
 .../basic_string_view/range_access/char/1.cc       |  47 +++
 .../basic_string_view/range_access/wchar_t/1.cc    |  47 +++
 .../requirements/explicit_instantiation/1.cc       |  26 ++
 .../requirements/explicit_instantiation/char/1.cc  |  23 ++
 .../explicit_instantiation/char16_t/1.cc           |  24 ++
 .../explicit_instantiation/char32_t/1.cc           |  24 ++
 .../explicit_instantiation/wchar_t/1.cc            |  23 ++
 .../basic_string_view/requirements/typedefs.cc     |  47 +++
 gdb/unittests/basic_string_view/typedefs.cc        |  36 ++
 gdb/unittests/basic_string_view/types/1.cc         |  43 +++
 72 files changed, 5270 insertions(+)
 create mode 100644 gdb/unittests/basic_string_view/capacity/1.cc
 create mode 100644 gdb/unittests/basic_string_view/capacity/empty_neg.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/char/3.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/cons/wchar_t/3.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/char/empty.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/char/front_back.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/wchar_t/empty.cc
 create mode 100644 gdb/unittests/basic_string_view/element_access/wchar_t/front_back.cc
 create mode 100644 gdb/unittests/basic_string_view/include.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/char/3.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/pod/10081-out.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/inserters/wchar_t/3.cc
 create mode 100644 gdb/unittests/basic_string_view/literals/types.cc
 create mode 100644 gdb/unittests/basic_string_view/literals/values.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/remove_prefix/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/remove_suffix/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/swap/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/modifiers/swap/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/char/13650.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/char/70483.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/wchar_t/13650.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/compare/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/copy/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/copy/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/data/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/data/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/char/3.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/char/4.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/wchar_t/3.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/find/wchar_t/4.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/char/3.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/rfind/wchar_t/3.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/string_conversion/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/substr/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operations/substr/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/operators/char/2.cc
 create mode 100644 gdb/unittests/basic_string_view/operators/wchar_t/2.cc
 create mode 100644 gdb/unittests/basic_string_view/range_access/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/range_access/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/explicit_instantiation/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc
 create mode 100644 gdb/unittests/basic_string_view/requirements/typedefs.cc
 create mode 100644 gdb/unittests/basic_string_view/typedefs.cc
 create mode 100644 gdb/unittests/basic_string_view/types/1.cc
Pedro Alves - April 9, 2018, 1:47 p.m.
On 04/07/2018 02:26 PM, Simon Marchi wrote:
> This patch copies the string_view tests from the gcc repository (commit
> 02a4441f002c).
> 
>   ${gcc}/libstdc++-v3/testsuite/21_strings/basic_string_view ->
>     ${binutils-gdb}/gdb/unittests/basic_string_view
> 
> The local modifications are done in the following patch, so that it's
> easier to review them.
> 

For completeness... :-) ... OK.

Thanks,
Pedro Alves

Patch

diff --git a/gdb/unittests/basic_string_view/capacity/1.cc b/gdb/unittests/basic_string_view/capacity/1.cc
new file mode 100644
index 000000000000..d49ecbd9dd53
--- /dev/null
+++ b/gdb/unittests/basic_string_view/capacity/1.cc
@@ -0,0 +1,162 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// string_view size, length
+
+#include <string_view>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+template<typename T>
+  struct A { };
+
+template<typename T>
+  bool
+  operator==(const A<T>&, const A<T>&) { return true; }
+
+template<typename T>
+  bool
+  operator<(const A<T>&, const A<T>&) { return true; }
+
+struct B { };
+
+// char_traits specialization
+namespace std
+{
+  template<>
+    struct char_traits<A<B> >
+    {
+      typedef A<B> 		char_type;
+      // Unsigned as wint_t in unsigned.
+      typedef unsigned long  	int_type;
+      typedef streampos 	pos_type;
+      typedef streamoff 	off_type;
+      typedef mbstate_t 	state_type;
+      
+      static void 
+      assign(char_type& __c1, const char_type& __c2)
+      { __c1 = __c2; }
+
+      static bool 
+      eq(const char_type& __c1, const char_type& __c2)
+      { return __c1 == __c2; }
+
+      static bool 
+      lt(const char_type& __c1, const char_type& __c2)
+      { return __c1 < __c2; }
+
+      static int 
+      compare(const char_type* __s1, const char_type* __s2, size_t __n)
+      { 
+	for (size_t __i = 0; __i < __n; ++__i)
+	  if (!eq(__s1[__i], __s2[__i]))
+	    return lt(__s1[__i], __s2[__i]) ? -1 : 1;
+	return 0; 
+      }
+
+      static size_t
+      length(const char_type* __s)
+      { 
+	const char_type* __p = __s; 
+	while (__p) 
+	  ++__p; 
+	return (__p - __s); 
+      }
+
+      static const char_type* 
+      find(const char_type* __s, size_t __n, const char_type& __a)
+      { 
+	for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
+	  if (*__p == __a) return __p;
+	return 0;
+      }
+
+      static char_type* 
+      move(char_type* __s1, const char_type* __s2, size_t __n)
+      { return (char_type*) memmove(__s1, __s2, __n * sizeof(char_type)); }
+
+      static char_type* 
+      copy(char_type* __s1, const char_type* __s2, size_t __n)
+      { return (char_type*) memcpy(__s1, __s2, __n * sizeof(char_type)); }
+
+      static char_type* 
+      assign(char_type* __s, size_t __n, char_type __a)
+      { 
+	for (char_type* __p = __s; __p < __s + __n; ++__p) 
+	  assign(*__p, __a);
+        return __s; 
+      }
+
+      static char_type 
+      to_char_type(const int_type&)
+      { return char_type(); }
+
+      static int_type 
+      to_int_type(const char_type&) { return int_type(); }
+
+      static bool 
+      eq_int_type(const int_type& __c1, const int_type& __c2)
+      { return __c1 == __c2; }
+
+      static int_type 
+      eof() { return static_cast<int_type>(-1); }
+
+      static int_type 
+      not_eof(const int_type& __c)
+      { return eq_int_type(__c, eof()) ? int_type(0) : __c; }
+    };
+} // namespace std
+
+void
+test01()
+{
+  std::basic_string_view<A<B>> str02;
+  typedef std::basic_string_view< A<B> >::size_type size_type_o;
+  size_type_o sz03;
+  size_type_o sz04;
+
+  // non-POD types: size, length, max_size, empty()
+  bool b01 = str02.empty();  
+  VERIFY( b01 == true );
+  sz03 = str02.size();
+  sz04 = str02.length();
+  VERIFY( sz03 == sz04 );
+  str02.data();
+  sz03 = str02.size();
+  sz04 = str02.length();
+  VERIFY( sz03 == sz04 );
+
+  sz03 = str02.max_size();  
+  VERIFY( sz03 >= sz04 );
+
+  sz03 = str02.size();
+  str02 = {};
+  b01 = str02.empty(); 
+  VERIFY( b01 == true );
+  sz04 = str02.size();  
+  VERIFY( sz03 >= sz04 );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/capacity/empty_neg.cc b/gdb/unittests/basic_string_view/capacity/empty_neg.cc
new file mode 100644
index 000000000000..4ea506365c03
--- /dev/null
+++ b/gdb/unittests/basic_string_view/capacity/empty_neg.cc
@@ -0,0 +1,28 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+void
+test01()
+{
+  std::string_view s;
+  s.empty();  // { dg-warning "ignoring return value" }
+}
diff --git a/gdb/unittests/basic_string_view/cons/char/1.cc b/gdb/unittests/basic_string_view/cons/char/1.cc
new file mode 100644
index 000000000000..f80ae92f2f80
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/char/1.cc
@@ -0,0 +1,68 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <string_view>
+#include <string>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+
+  // basic_string_view()
+  const std::string_view str00{};
+  VERIFY( str00.length() == 0 );
+  VERIFY( str00.data() == nullptr );
+
+  // basic_string_view(const char*)
+  const char str_lit01[] = "rodeo beach, marin";
+  const std::string_view str01{str_lit01};
+  VERIFY( str01.length() == 18 );
+  VERIFY( str01.data() == str_lit01 );
+  const std::string_view str02{"baker beach, san francisco"};
+  VERIFY( str02.length() == 26 );
+
+  // basic_string_view(const string_view&)
+  std::string_view str04{str01};
+  VERIFY( str04.length() == str01.length() );
+  VERIFY( str04.data() == str01.data() );
+
+  // basic_string_view(const char* s)
+  csize_type len_lit01 = strlen(str_lit01);
+  std::string_view str05{str_lit01, len_lit01};
+  VERIFY( str05.length() == len_lit01 );
+  VERIFY( str05.data() == str_lit01 );
+
+  // basic_string_view(basic_string& s)
+  std::string istr07(10, 'z');
+  std::string_view str07{istr07};
+  VERIFY( str07.length() == 10 );
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/cons/char/2.cc b/gdb/unittests/basic_string_view/cons/char/2.cc
new file mode 100644
index 000000000000..8dbca7a621e7
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/char/2.cc
@@ -0,0 +1,47 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <new>
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test03()
+{
+  const char* with_nulls = "This contains \0 a zero byte.";
+
+  // These are tests to see how basic_string_view handles data with NUL
+  // bytes.  Obviously basic_string_view(char*) will halt at the first one, but
+  // nothing else should.
+  std::string_view s1(with_nulls, 28);
+  VERIFY( s1.size() == 28 );
+  std::string_view s2(s1);
+  VERIFY( s2.size() == 28 );
+}
+
+int
+main()
+{ 
+  test03();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/cons/char/3.cc b/gdb/unittests/basic_string_view/cons/char/3.cc
new file mode 100644
index 000000000000..c892cbc62720
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/char/3.cc
@@ -0,0 +1,39 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <string_view>
+#include <vector>
+#include <testsuite_hooks.h>
+
+void
+test05()
+{
+  char const * s = 0;
+  std::string_view zero_length_built_with_NULL(s, 0);
+}
+
+int
+main()
+{ 
+  test05();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/cons/wchar_t/1.cc b/gdb/unittests/basic_string_view/cons/wchar_t/1.cc
new file mode 100644
index 000000000000..4f935d57e469
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/wchar_t/1.cc
@@ -0,0 +1,68 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <string_view>
+#include <string>
+#include <cwchar>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+
+  // basic_string_view()
+  const std::wstring_view str00{};
+  VERIFY( str00.length() == 0 );
+  VERIFY( str00.data() == nullptr );
+
+  // basic_string_view(const char*)
+  const wchar_t str_lit01[] = L"rodeo beach, marin";
+  const std::wstring_view str01{str_lit01};
+  VERIFY( str01.length() == 18 );
+  VERIFY( str01.data() == str_lit01 );
+  const std::wstring_view str02{L"baker beach, san francisco"};
+  VERIFY( str02.length() == 26 );
+
+  // basic_string_view(const string_view&)
+  std::wstring_view str04{str01};
+  VERIFY( str04.length() == str01.length() );
+  VERIFY( str04.data() == str01.data() );
+
+  // basic_string_view(const char* s)
+  csize_type len_lit01 = wcslen(str_lit01);
+  std::wstring_view str05{str_lit01, len_lit01};
+  VERIFY( str05.length() == len_lit01 );
+  VERIFY( str05.data() == str_lit01 );
+
+  // basic_string_view(basic_string& s)
+  std::wstring istr07(10, L'z');
+  std::wstring_view str07{istr07};
+  VERIFY( str07.length() == 10 );
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/cons/wchar_t/2.cc b/gdb/unittests/basic_string_view/cons/wchar_t/2.cc
new file mode 100644
index 000000000000..3134ec0781e9
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/wchar_t/2.cc
@@ -0,0 +1,45 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test03()
+{
+  const wchar_t* with_nulls = L"This contains \0 a zero byte.";
+
+  // These are tests to see how basic_string_view handles data with NUL
+  // bytes.  Obviously basic_string_view(char*) will halt at the first one, but
+  // nothing else should.
+  std::wstring_view s1 (with_nulls, 28);
+  VERIFY( s1.size() == 28 );
+  std::wstring_view s2 (s1);
+  VERIFY( s2.size() == 28 );
+}
+
+int
+main()
+{ 
+  test03();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/cons/wchar_t/3.cc b/gdb/unittests/basic_string_view/cons/wchar_t/3.cc
new file mode 100644
index 000000000000..c49dc2579868
--- /dev/null
+++ b/gdb/unittests/basic_string_view/cons/wchar_t/3.cc
@@ -0,0 +1,38 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view constructors.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test05()
+{
+  wchar_t const * s = 0;
+  std::wstring_view zero_length_built_with_NULL(s, 0);
+}
+
+int
+main()
+{ 
+  test05();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/char/1.cc b/gdb/unittests/basic_string_view/element_access/char/1.cc
new file mode 100644
index 000000000000..03c588efb0d7
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/char/1.cc
@@ -0,0 +1,70 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string element access
+
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+  csize_type csz01, csz02;
+
+  const std::string_view str01("tamarindo, costa rica");
+  std::string_view str02("41st street beach, capitola, california");
+  std::string_view str03;
+
+  // const_reference operator[] (size_type pos) const;
+  csz01 = str01.size();
+  cref cref1 = str01[csz01 - 1];
+  VERIFY( cref1 == 'a' );
+  // Undefined behavior at size().
+  //cref cref2 = str01[csz01];
+  //VERIFY( cref2 == char() );
+
+  // const_reference at(size_type pos) const;
+  csz01 = str01.size();
+  cref cref3 = str01.at(csz01 - 1);
+  VERIFY( cref3 == 'a' );
+  try
+  {
+    str01.at(csz01);
+    VERIFY( false ); // Should not get here, as exception thrown.
+  }
+  catch (std::out_of_range& fail)
+  {
+    VERIFY( true );
+  }
+  catch (...)
+  {
+    VERIFY( false );
+  }
+}
+
+int
+main()
+{ 
+  test01();
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/char/2.cc b/gdb/unittests/basic_string_view/element_access/char/2.cc
new file mode 100644
index 000000000000..4ee2b64a0bba
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/char/2.cc
@@ -0,0 +1,30 @@ 
+// { dg-do run { xfail *-*-* } }
+// { dg-options "-std=gnu++17 -O0" }
+// { dg-require-debug-mode "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+int
+main()
+{
+  typedef std::string_view string_view_type;
+  string_view_type s;
+  s[0]; // abort
+}
diff --git a/gdb/unittests/basic_string_view/element_access/char/empty.cc b/gdb/unittests/basic_string_view/element_access/char/empty.cc
new file mode 100644
index 000000000000..fad5eb798ba6
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/char/empty.cc
@@ -0,0 +1,38 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 3 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+//
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+int
+main()
+{
+  {
+    std::string_view empty;
+    VERIFY( empty.empty() );
+  }
+
+  {
+    const std::string_view empty;
+    VERIFY( empty.empty() );
+  }
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/char/front_back.cc b/gdb/unittests/basic_string_view/element_access/char/front_back.cc
new file mode 100644
index 000000000000..efff787e365e
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/char/front_back.cc
@@ -0,0 +1,42 @@ 
+// { dg-options "-std=gnu++17" }
+// { dg-require-string-conversions "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::string_view str("ramifications");
+  const std::string_view cstr("melodien");
+
+  VERIFY( str.front() == 'r' );
+  VERIFY( str.back() == 's' );
+  VERIFY( cstr.front() == 'm' );
+  VERIFY( cstr.back() == 'n' );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc b/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc
new file mode 100644
index 000000000000..b74ee29f316d
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc
@@ -0,0 +1,71 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view element access
+
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type csz01, csz02;
+
+  const std::wstring_view str01(L"tamarindo, costa rica");
+  std::wstring_view str02(L"41st street beach, capitola, california");
+  std::wstring_view str03;
+
+  // const_reference operator[] (size_type pos) const;
+  csz01 = str01.size();
+  cref cref1 = str01[csz01 - 1];
+  VERIFY( cref1 == L'a' );
+  // Undefined behavior at size().
+  //cref cref2 = str01[csz01];
+  //VERIFY( cref2 == wchar_t() );
+
+  // const_reference at(size_type pos) const;
+  csz01 = str01.size();
+  cref cref3 = str01.at(csz01 - 1);
+  VERIFY( cref3 == L'a' );
+  try
+  {
+    str01.at(csz01);
+    VERIFY( false ); // Should not get here, as exception thrown.
+  }
+  catch (std::out_of_range& fail)
+  {
+    VERIFY( true );
+  }
+  catch (...)
+  {
+    VERIFY( false );
+  }
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/wchar_t/2.cc b/gdb/unittests/basic_string_view/element_access/wchar_t/2.cc
new file mode 100644
index 000000000000..5b7421f2f304
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/wchar_t/2.cc
@@ -0,0 +1,32 @@ 
+// { dg-do run { xfail *-*-* } }
+// { dg-options "-std=gnu++17 -O0" }
+// { dg-require-debug-mode "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+// libstdc++/21674
+// NB: Should work without any inlining or optimizations (ie. -O0).
+int
+main()
+{
+  typedef std::wstring_view string_view_type;
+  string_view_type s;
+  s[0]; // abort
+}
diff --git a/gdb/unittests/basic_string_view/element_access/wchar_t/empty.cc b/gdb/unittests/basic_string_view/element_access/wchar_t/empty.cc
new file mode 100644
index 000000000000..b1ac051b91dd
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/wchar_t/empty.cc
@@ -0,0 +1,38 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+//
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+int
+main()
+{
+  {
+    std::wstring_view empty;
+    VERIFY( empty.empty() );
+  }
+
+  {
+    const std::wstring_view empty;
+    VERIFY( empty.empty() );
+  }
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/element_access/wchar_t/front_back.cc b/gdb/unittests/basic_string_view/element_access/wchar_t/front_back.cc
new file mode 100644
index 000000000000..a7c8483f6fc7
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/wchar_t/front_back.cc
@@ -0,0 +1,42 @@ 
+// { dg-options "-std=gnu++17" }
+// { dg-require-string-conversions "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::wstring_view str(L"ramifications");
+  const std::wstring_view cstr(L"melodien");
+
+  VERIFY( str.front() == L'r' );
+  VERIFY( str.back() == L's' );
+  VERIFY( cstr.front() == L'm' );
+  VERIFY( cstr.back() == L'n' );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/include.cc b/gdb/unittests/basic_string_view/include.cc
new file mode 100644
index 000000000000..59dc47dc3226
--- /dev/null
+++ b/gdb/unittests/basic_string_view/include.cc
@@ -0,0 +1,25 @@ 
+// -*- C++ -*-
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// NB: This issue affected only debug-mode.
+
+// { dg-options "-std=gnu++17 -fno-rtti" }
+// { dg-do compile }
+
+#include <string_view>
diff --git a/gdb/unittests/basic_string_view/inserters/char/1.cc b/gdb/unittests/basic_string_view/inserters/char/1.cc
new file mode 100644
index 000000000000..26bd0fdc918d
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/char/1.cc
@@ -0,0 +1,65 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, istreams, and ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+#include <string_view>
+#include <stdexcept>
+#include <sstream>
+#include <fstream>
+#include <iostream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+
+  const std::string_view str01("sailing grand traverse bay\n"
+	       "\t\t\t    from Elk Rapids to the point reminds me of miles");
+    
+  // ostream& operator<<(ostream&, const basic_string_view&)
+  std::ostringstream ostrs01;
+  try 
+    {
+      ostrs01 << str01;
+      VERIFY( ostrs01.str() == str01 );
+    }
+  catch(std::exception& fail) 
+    {
+      VERIFY( false );
+    }
+  
+  std::string_view hello_world;
+  std::cout << hello_world;
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/char/2.cc b/gdb/unittests/basic_string_view/inserters/char/2.cc
new file mode 100644
index 000000000000..6562d58615df
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/char/2.cc
@@ -0,0 +1,93 @@ 
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+// { dg-options "-std=gnu++17" }
+// { dg-require-fileio "" }
+
+#include <string_view>
+#include <string>
+#include <fstream>
+#include <iostream>
+#include <testsuite_hooks.h>
+
+// testing basic_filebuf::xsputn via stress testing with large string_views
+// based on a bug report libstdc++ 9
+// mode == out
+void
+test05(std::size_t size)
+{
+  bool test = true;
+
+  const char filename[] = "inserters_extractors-2.txt";
+  const char fillc = 'f';
+  std::ofstream ofs(filename);
+  std::string str(size, fillc);
+  std::string_view strv{str};
+
+  // sanity checks
+  VERIFY( str.size() == size );
+  VERIFY( ofs.good() );
+
+  // stress test
+  ofs << str << std::endl;
+  if (!ofs.good()) 
+    test = false;
+
+  ofs << str << std::endl;
+  if (!ofs.good()) 
+    test = false;
+
+  VERIFY( str.size() == size );
+  VERIFY( ofs.good() );
+
+  ofs.close();
+
+  // sanity check on the written file
+  std::ifstream ifs(filename);
+  std::size_t count = 0;
+  char c;
+  while (count <= (2 * size) + 4)
+    {
+      ifs >> c;
+      if (ifs.good() && c == fillc)
+	{
+	  ++count;
+	  c = '0';
+	}
+      else 
+	break;
+    }
+
+  VERIFY( count == 2 * size );
+}
+
+int
+main()
+{
+  test05(1); 
+  test05(1000); 
+  test05(10000);
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/char/3.cc b/gdb/unittests/basic_string_view/inserters/char/3.cc
new file mode 100644
index 000000000000..7905661396da
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/char/3.cc
@@ -0,0 +1,54 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, and ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+#include <string_view>
+#include <sstream>
+#include <iomanip>
+#include <testsuite_hooks.h>
+
+// libstdc++/2830
+void
+test09()
+{
+  std::string_view foo{"peace\0\0\0& love"};
+
+  std::ostringstream oss1;
+  oss1 << foo;
+  VERIFY( oss1.str() == foo );
+
+  std::ostringstream oss2;
+  oss2.width(20);
+  oss2 << foo;
+  VERIFY( oss2.str() != foo );
+  VERIFY( oss2.str().size() == 20 );
+}
+
+int
+main()
+{ 
+  test09();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/pod/10081-out.cc b/gdb/unittests/basic_string_view/inserters/pod/10081-out.cc
new file mode 100644
index 000000000000..15538a45386c
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/pod/10081-out.cc
@@ -0,0 +1,75 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// class basic_istream::sentry
+
+#include <string_view>
+#include <ostream>
+#include <sstream>
+#include <locale>
+#include <typeinfo>
+#include <testsuite_hooks.h>
+#include <testsuite_character.h>
+
+void
+test01()
+{
+  using namespace std;
+
+  using __gnu_test::pod_ushort;
+  typedef basic_string_view<pod_ushort> 	string_type;
+  typedef basic_stringbuf<pod_ushort> 	stringbuf_type;
+  typedef basic_ostream<pod_ushort> 	ostream_type;
+
+  string_type str;
+  stringbuf_type strbuf01;
+  ostream_type stream(&strbuf01);
+
+  try
+    {
+      stream << str;
+    }
+  catch (std::bad_cast& obj)
+    {
+      // Ok, throws bad_cast because locale has no ctype facet.
+    }
+  catch (...)
+    {
+      VERIFY( false );
+    }
+
+  const std::locale loc(std::locale::classic(), new std::ctype<pod_ushort>);
+  stream.imbue(loc);
+  try
+    {
+      stream << str;
+    }
+  catch (...)
+    {
+      VERIFY( false );
+    }
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/wchar_t/1.cc b/gdb/unittests/basic_string_view/inserters/wchar_t/1.cc
new file mode 100644
index 000000000000..c5cbdba25640
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/wchar_t/1.cc
@@ -0,0 +1,70 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, and ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+#include <string_view>
+#include <stdexcept>
+#include <sstream>
+#include <fstream>
+#include <iostream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+
+  const std::wstring_view str01(L"sailing grand traverse bay\n"
+	       L"\t\t\t    from Elk Rapids to the point reminds me of miles");
+  const std::wstring_view str02(L"sailing");
+  const std::wstring_view str03(L"grand");
+  const std::wstring_view str04(L"traverse");
+  const std::wstring_view str05;
+  std::wstring_view str10;
+
+  // ostream& operator<<(ostream&, const basic_string_view&)
+  std::wostringstream ostrs01;
+  try 
+    {
+      ostrs01 << str01;
+      VERIFY( ostrs01.str() == str01 );
+    }
+  catch(std::exception& fail) 
+    {
+      VERIFY( false );
+    }
+  
+  std::wstring_view hello_world;
+  std::wcout << hello_world;
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/wchar_t/2.cc b/gdb/unittests/basic_string_view/inserters/wchar_t/2.cc
new file mode 100644
index 000000000000..ebb275213258
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/wchar_t/2.cc
@@ -0,0 +1,91 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, istreams, and ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+#include <string_view>
+#include <string>
+#include <fstream>
+#include <iostream>
+#include <testsuite_hooks.h>
+
+// testing basic_filebuf::xsputn via stress testing with large string_views
+// based on a bug report libstdc++ 9
+// mode == out
+void
+test05(std::size_t size)
+{
+  bool test = true;
+
+  const char filename[] = "inserters_extractors-2.txt";
+  const wchar_t fillc = L'f';
+  std::wofstream ofs(filename);
+  std::wstring str(size, fillc);
+  std::wstring_view strv(str);
+
+  // sanity checks
+  VERIFY( str.size() == size );
+  VERIFY( ofs.good() );
+
+  // stress test
+  ofs << str << std::endl;
+  if (!ofs.good()) 
+    test = false;
+
+  ofs << str << std::endl;
+  if (!ofs.good()) 
+    test = false;
+
+  VERIFY( str.size() == size );
+  VERIFY( ofs.good() );
+
+  ofs.close();
+
+  // sanity check on the written file
+  std::wifstream ifs(filename);
+  std::size_t count = 0;
+  wchar_t c;
+  while (count <= (2 * size) + 4)
+    {
+      ifs >> c;
+      if (ifs.good() && c == fillc)
+	{
+	  ++count;
+	  c = '0';
+	}
+      else 
+	break;
+    }
+
+  VERIFY( count == 2 * size );
+}
+
+int
+main()
+{
+  test05(1); 
+  test05(1000); 
+  test05(10000);
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/inserters/wchar_t/3.cc b/gdb/unittests/basic_string_view/inserters/wchar_t/3.cc
new file mode 100644
index 000000000000..569c4213a7fa
--- /dev/null
+++ b/gdb/unittests/basic_string_view/inserters/wchar_t/3.cc
@@ -0,0 +1,53 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// inserters
+
+// NB: This file is predicated on sstreams, istreams, and ostreams
+// working, not to mention other major details like char_traits, and
+// all of the string_view class.
+
+#include <string_view>
+#include <sstream>
+#include <iomanip>
+#include <testsuite_hooks.h>
+
+void
+test09()
+{
+  std::wstring_view foo{L"peace\0\0\0& love"};
+  
+  std::wostringstream oss1;
+  oss1 << foo;
+  VERIFY( oss1.str() == foo );
+  
+  std::wostringstream oss2;
+  oss2.width(20);
+  oss2 << foo;
+  VERIFY( oss2.str() != foo );
+  VERIFY( oss2.str().size() == 20 );
+}
+
+int
+main()
+{ 
+  test09();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/literals/types.cc b/gdb/unittests/basic_string_view/literals/types.cc
new file mode 100644
index 000000000000..8b3b467efc43
--- /dev/null
+++ b/gdb/unittests/basic_string_view/literals/types.cc
@@ -0,0 +1,45 @@ 
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <type_traits>
+
+void
+test01()
+{
+  using namespace std::literals::string_view_literals;
+
+  static_assert(std::is_same<decltype("Hello"sv), std::string_view>::value,
+		"\"Hello\"s is std::string_view");
+
+  static_assert(std::is_same<decltype(u8"Hello"sv), std::string_view>::value,
+		"u8\"Hello\"s is std::string_view");
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+  static_assert(std::is_same<decltype(L"Hello"sv), std::wstring_view>::value,
+		"L\"Hello\"s is std::wstring_view");
+#endif
+
+  static_assert(std::is_same<decltype(u"Hello"sv), std::u16string_view>::value,
+		"u\"Hello\"s is std::u16string_view");
+
+  static_assert(std::is_same<decltype(U"Hello"sv), std::u32string_view>::value,
+		"U\"Hello\"s is std::u32string_view");
+}
diff --git a/gdb/unittests/basic_string_view/literals/values.cc b/gdb/unittests/basic_string_view/literals/values.cc
new file mode 100644
index 000000000000..b2897a136b8b
--- /dev/null
+++ b/gdb/unittests/basic_string_view/literals/values.cc
@@ -0,0 +1,72 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using namespace std::literals::string_view_literals;
+
+  std::string_view planet = "Mercury"sv;
+#ifdef _GLIBCXX_USE_WCHAR_T
+  std::wstring_view wplanet = L"Venus"sv;
+#endif
+  std::string_view u8planet = u8"Mars"sv;
+  std::u16string_view u16planet = u"Jupiter"sv;
+  std::u32string_view u32planet = U"Saturn"sv;
+
+  VERIFY( planet == std::string_view("Mercury") );
+#ifdef _GLIBCXX_USE_WCHAR_T
+  VERIFY( wplanet == std::wstring_view(L"Venus") );
+#endif
+  VERIFY( u8planet == std::string_view(u8"Mars") );
+  VERIFY( u16planet == std::u16string_view(u"Jupiter") );
+  VERIFY( u32planet == std::u32string_view(U"Saturn") );
+}
+
+void
+test02()
+{
+  using namespace std::literals::string_view_literals;
+
+  std::string_view planet_cratered = "Mercury\0cratered"sv;
+#ifdef _GLIBCXX_USE_WCHAR_T
+  std::wstring_view wplanet_cratered = L"Venus\0cratered"sv;
+#endif
+  std::string_view u8planet_cratered = u8"Mars\0cratered"sv;
+  std::u16string_view u16planet_cratered = u"Jupiter\0cratered"sv;
+  std::u32string_view u32planet_cratered = U"Saturn\0cratered"sv;
+
+  VERIFY( planet_cratered == std::string_view("Mercury\0cratered", 16) );
+#ifdef _GLIBCXX_USE_WCHAR_T
+  VERIFY( wplanet_cratered == std::wstring_view(L"Venus\0cratered", 14) );
+#endif
+  VERIFY( u8planet_cratered == std::string_view(u8"Mars\0cratered", 13) );
+  VERIFY( u16planet_cratered == std::u16string_view(u"Jupiter\0cratered", 16) );
+  VERIFY( u32planet_cratered == std::u32string_view(U"Saturn\0cratered", 15) );
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}
diff --git a/gdb/unittests/basic_string_view/modifiers/remove_prefix/char/1.cc b/gdb/unittests/basic_string_view/modifiers/remove_prefix/char/1.cc
new file mode 100644
index 000000000000..ba08a98eeaec
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/remove_prefix/char/1.cc
@@ -0,0 +1,61 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using std::string_view;
+
+  string_view str0{"olympus mons"};
+  string_view::pointer p = str0.data();
+  str0.remove_prefix(4);
+  VERIFY( str0.data() == p + 4);
+  VERIFY( str0.length() == 8 );
+  VERIFY( str0 == string_view{"pus mons"} );
+}
+
+constexpr bool
+test02()
+{
+  using std::string_view;
+
+  string_view str0{"olympus mons"};
+  string_view::pointer p = str0.data();
+  str0.remove_prefix(4);
+  if ( str0.data() != p + 4)
+    return false;
+  if ( str0.length() != 8 )
+    return false;
+  if ( str0 != string_view{"pus mons"} )
+    return false;
+
+  return true;
+}
+
+int
+main()
+{ 
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc b/gdb/unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc
new file mode 100644
index 000000000000..3c6911824c6a
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc
@@ -0,0 +1,61 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using std::wstring_view;
+
+  wstring_view str0{L"olympus mons"};
+  wstring_view::pointer p = str0.data();
+  str0.remove_prefix(4);
+  VERIFY( str0.data() == p + 4);
+  VERIFY( str0.length() == 8 );
+  VERIFY( str0 == wstring_view{L"pus mons"} );
+}
+
+constexpr bool
+test02()
+{
+  using std::wstring_view;
+
+  wstring_view str0{L"olympus mons"};
+  wstring_view::pointer p = str0.data();
+  str0.remove_prefix(4);
+  if ( str0.data() != p + 4)
+    return false;
+  if ( str0.length() != 8 )
+    return false;
+  if ( str0 != wstring_view{L"pus mons"} )
+    return false;
+
+  return true;
+}
+
+int
+main()
+{ 
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/modifiers/remove_suffix/char/1.cc b/gdb/unittests/basic_string_view/modifiers/remove_suffix/char/1.cc
new file mode 100644
index 000000000000..1b71ee936e8c
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/remove_suffix/char/1.cc
@@ -0,0 +1,61 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using std::string_view;
+
+  string_view str0{"olympus mons"};
+  string_view::pointer p = str0.data();
+  str0.remove_suffix(2);
+  VERIFY( str0.data() == p);
+  VERIFY( str0.length() == 10 );
+  VERIFY( str0 == string_view{"olympus mo"} );
+}
+
+constexpr bool
+test02()
+{
+  using std::string_view;
+
+  string_view str0{"olympus mons"};
+  string_view::pointer p = str0.data();
+  str0.remove_suffix(2);
+  if ( str0.data() != p)
+    return false;
+  if ( str0.length() != 10 )
+    return false;
+  if ( str0 != string_view{"olympus mo"} )
+    return false;
+
+  return true;
+}
+
+int
+main()
+{ 
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc b/gdb/unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc
new file mode 100644
index 000000000000..0f94a092ad69
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc
@@ -0,0 +1,61 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using std::wstring_view;
+
+  wstring_view str0{L"olympus mons"};
+  wstring_view::pointer p = str0.data();
+  str0.remove_suffix(2);
+  VERIFY( str0.data() == p);
+  VERIFY( str0.length() == 10 );
+  VERIFY( str0 == wstring_view{L"olympus mo"} );
+}
+
+constexpr bool
+test02()
+{
+  using std::wstring_view;
+
+  wstring_view str0{L"olympus mons"};
+  wstring_view::pointer p = str0.data();
+  str0.remove_suffix(2);
+  if ( str0.data() != p)
+    return false;
+  if ( str0.length() != 10 )
+    return false;
+  if ( str0 != wstring_view{L"olympus mo"} )
+    return false;
+
+  return true;
+}
+
+int
+main()
+{ 
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/modifiers/swap/char/1.cc b/gdb/unittests/basic_string_view/modifiers/swap/char/1.cc
new file mode 100644
index 000000000000..90d26692599c
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/swap/char/1.cc
@@ -0,0 +1,35 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+constexpr bool
+test01()
+{
+  using std::string_view;
+
+  string_view s1{"last"};
+  string_view s2{"first"};
+
+  s1.swap(s2);
+  return s1 == "first" && s2 == "last";
+}
+
+static_assert( test01() );
diff --git a/gdb/unittests/basic_string_view/modifiers/swap/wchar_t/1.cc b/gdb/unittests/basic_string_view/modifiers/swap/wchar_t/1.cc
new file mode 100644
index 000000000000..bd757ecfaa93
--- /dev/null
+++ b/gdb/unittests/basic_string_view/modifiers/swap/wchar_t/1.cc
@@ -0,0 +1,35 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+constexpr bool
+test01()
+{
+  using std::wstring_view;
+
+  wstring_view s1{L"last"};
+  wstring_view s2{L"first"};
+
+  s1.swap(s2);
+  return s1 == L"first" && s2 == L"last";
+}
+
+static_assert( test01() );
diff --git a/gdb/unittests/basic_string_view/operations/compare/char/1.cc b/gdb/unittests/basic_string_view/operations/compare/char/1.cc
new file mode 100644
index 000000000000..46691ebd52a1
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/char/1.cc
@@ -0,0 +1,132 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::compare
+// int compare(const basic_string_view& str) const;
+// int compare(size_type pos1, size_type n1, const basic_string_view& str) const;
+// int compare(size_type pos1, size_type n1, const basic_string_view& str,
+//             size_type pos2, size_type n2) const;
+// int compare(const charT* s) const;
+// int compare(size_type pos1, size_type n1,
+//             const charT* s, size_type n2 = npos) const;
+
+// NB compare should be thought of as a lexographical compare, ie how
+// things would be sorted in a dictionary.
+
+#include <string_view>
+#include <cstring>
+#include <testsuite_hooks.h>
+
+enum want_value {lt=0, z=1, gt=2};
+
+int
+test_value(int result, want_value expected);
+
+int
+test_value(int result, want_value expected)
+{
+  bool pass = false;
+
+  switch (expected) {
+  case lt:
+    if (result < 0)
+      pass = true;
+    break;
+  case z:
+    if (!result)
+      pass = true;
+    break;
+  case gt:
+    if (result > 0)
+      pass = true;
+    break;
+  default:
+    pass = false; //should not get here
+  }
+  VERIFY(pass);
+  return 0;
+}
+
+int
+test01()
+{
+  using std::string_view;
+
+  string_view 	str_0("costa rica");
+  string_view 	str_1("costa marbella");
+  string_view 	str_2;
+
+  //sanity check
+  test_value(strcmp("costa marbella", "costa rica"), lt);
+  test_value(strcmp("costa rica", "costa rica"), z);
+  test_value(strcmp(str_1.data(), str_0.data()), lt);
+  test_value(strcmp(str_0.data(), str_1.data()), gt);
+  test_value(strncmp(str_1.data(), str_0.data(), 6), z);
+  test_value(strncmp(str_1.data(), str_0.data(), 14), lt);
+  test_value(memcmp(str_1.data(), str_0.data(), 6), z);
+  test_value(memcmp(str_1.data(), str_0.data(), 10), lt);
+  test_value(memcmp("costa marbella", "costa rica", 10), lt);
+
+  // int compare(const basic_string_view& str) const;
+  test_value(str_0.compare(str_1), gt); //because r>m
+  test_value(str_1.compare(str_0), lt); //because m<r
+  str_2 = str_0;
+  test_value(str_2.compare(str_0), z);
+  str_2 = "cost";
+  test_value(str_2.compare(str_0), lt);
+  str_2 = "costa ricans";
+  test_value(str_2.compare(str_0), gt);
+
+  // int compare(size_type pos1, size_type n1, const basic_string_view& str) const;
+  test_value(str_1.compare(0, 6, str_0), lt);
+  str_2 = "cost";
+  test_value(str_1.compare(0, 4, str_2), z);
+  test_value(str_1.compare(0, 5, str_2), gt);
+
+  // int compare(size_type pos1, size_type n1, const basic_string_view& str,
+  //		 size_type pos2, size_type n2) const;
+  test_value(str_1.compare(0, 6, str_0, 0, 6), z);
+  test_value(str_1.compare(0, 7, str_0, 0, 7), lt);
+  test_value(str_0.compare(0, 7, str_1, 0, 7), gt);
+
+  // int compare(const charT* s) const;
+  test_value(str_0.compare("costa marbella"), gt);
+  test_value(str_1.compare("costa rica"), lt);
+  str_2 = str_0;
+  test_value(str_2.compare("costa rica"), z);
+  test_value(str_2.compare("cost"), gt);
+  test_value(str_2.compare("costa ricans"), lt);
+
+  // int compare(size_type pos, size_type n1, const charT* str,
+  //             size_type n2 = npos) const;
+  test_value(str_1.compare(0, 6, "costa rica", 0, 6), z);
+  test_value(str_1.compare(0, 7, "costa rica", 0, 7), lt);
+  test_value(str_0.compare(0, 7, "costa marbella", 0, 7), gt);
+
+  return 0;
+}
+
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/compare/char/13650.cc b/gdb/unittests/basic_string_view/operations/compare/char/13650.cc
new file mode 100644
index 000000000000..ef9df20e6eec
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/char/13650.cc
@@ -0,0 +1,49 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::compare [lib.string_view::compare]
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// libstdc++/13650
+void
+test01()
+{
+  using std::string_view;
+
+  const char lit_01[]{ 'w', 'e', '\0', 'r', 'd' };
+  const char lit_02[]{ 'w', 'e', 'i', '\0', 'd' };
+
+  const char lit_ref_a[]{ 'w', 'e', '\0', 'q', 'd' };
+  const string_view str_a(lit_ref_a, 5);
+  VERIFY( str_a.compare(0, 5, lit_01, 5) < 0 );
+
+  const char lit_ref_b[]{ 'w', 'e', 'i' };
+  const string_view str_b(lit_ref_b, 3);
+  VERIFY( str_b.compare(0, 3, lit_02, 5) < 0 );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/compare/char/2.cc b/gdb/unittests/basic_string_view/operations/compare/char/2.cc
new file mode 100644
index 000000000000..ad9945a4dc10
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/char/2.cc
@@ -0,0 +1,30 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+constexpr char c1[] = "one";
+constexpr char c2[] = "two";
+
+constexpr std::string_view s1{c1};
+constexpr std::string_view s2{c2};
+
+constexpr int n1 = s1.compare(s1);
+constexpr int n2 = s1.compare(s2);
diff --git a/gdb/unittests/basic_string_view/operations/compare/char/70483.cc b/gdb/unittests/basic_string_view/operations/compare/char/70483.cc
new file mode 100644
index 000000000000..5954d570fdc4
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/char/70483.cc
@@ -0,0 +1,89 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+struct constexpr_char_traits : std::char_traits<char>
+{
+  static constexpr size_t
+  length(const char* val)
+  {
+    size_t res = 0;
+    for (; val[res] != '\0'; ++res)
+      ;
+    return res;
+  }
+
+  static constexpr int
+  compare(const char* lhs, const char* rhs, std::size_t count)
+  {
+    for (size_t pos = 0; pos < count; ++pos)
+    {
+      if (lhs[pos] != rhs[pos])
+        return lhs[pos] - rhs[pos];
+    }
+    return 0;
+  }
+};
+
+using string_view = std::basic_string_view<char, constexpr_char_traits>;
+
+constexpr
+string_view get()
+{
+    string_view res = "x::";
+    string_view start_pattern = "x";
+    res = res.substr(res.find(start_pattern) + start_pattern.size());
+    res = res.substr(0, res.find_first_of(";]"));
+    res = res.substr(res.rfind("::"));
+    return res;
+}
+
+static_assert( get() == get() );
+
+using std::u16string_view;
+
+constexpr
+u16string_view get16()
+{
+    u16string_view res = u"x::";
+    u16string_view start_pattern = u"x";
+    res = res.substr(res.find(start_pattern) + start_pattern.size());
+    res = res.substr(0, res.find_first_of(u";]"));
+    res = res.substr(res.rfind(u"::"));
+    return res;
+}
+
+static_assert( get16() == get16() );
+
+using std::u32string_view;
+
+constexpr
+u32string_view get32()
+{
+    u32string_view res = U"x::";
+    u32string_view start_pattern = U"x";
+    res = res.substr(res.find(start_pattern) + start_pattern.size());
+    res = res.substr(0, res.find_first_of(U";]"));
+    res = res.substr(res.rfind(U"::"));
+    return res;
+}
+
+static_assert( get32() == get32() );
diff --git a/gdb/unittests/basic_string_view/operations/compare/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/compare/wchar_t/1.cc
new file mode 100644
index 000000000000..15de7ccca646
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/wchar_t/1.cc
@@ -0,0 +1,133 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::compare
+// int compare(const basic_string_view& str) const;
+// int compare(size_type pos1, size_type n1, const basic_string_view& str) const;
+// int compare(size_type pos1, size_type n1, const basic_string_view& str,
+//             size_type pos2, size_type n2) const;
+// int compare(const charT* s) const;
+// int compare(size_type pos1, size_type n1,
+//             const charT* s, size_type n2 = npos) const;
+
+// NB compare should be thought of as a lexographical compare, ie how
+// things would be sorted in a dictionary.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+enum want_value {lt=0, z=1, gt=2};
+
+int
+test_value(int result, want_value expected);
+
+int
+test_value(int result, want_value expected)
+{
+  bool pass = false;
+
+  switch (expected) {
+  case lt:
+    if (result < 0)
+      pass = true;
+    break;
+  case z:
+    if (!result)
+      pass = true;
+    break;
+  case gt:
+    if (result > 0)
+      pass = true;
+    break;
+  default:
+    pass = false; //should not get here
+  }
+
+  VERIFY(pass);
+  return 0;
+}
+
+
+int
+test01()
+{
+  using std::wstring_view;
+
+  wstring_view 	str_0(L"costa rica");
+  wstring_view 	str_1(L"costa marbella");
+  wstring_view 	str_2;
+
+  //sanity check
+  test_value(wcscmp(L"costa marbella", L"costa rica"), lt);
+  test_value(wcscmp(L"costa rica", L"costa rica"), z);
+  test_value(wcscmp(str_1.data(), str_0.data()), lt);
+  test_value(wcscmp(str_0.data(), str_1.data()), gt);
+  test_value(wcsncmp(str_1.data(), str_0.data(), 6), z);
+  test_value(wcsncmp(str_1.data(), str_0.data(), 14), lt);
+  test_value(wmemcmp(str_1.data(), str_0.data(), 6), z);
+  test_value(wmemcmp(str_1.data(), str_0.data(), 14), lt);
+  test_value(wmemcmp(L"costa marbella", L"costa rica", 14), lt);
+
+  // int compare(const basic_string_view& str) const;
+  test_value(str_0.compare(str_1), gt); //because r>m
+  test_value(str_1.compare(str_0), lt); //because m<r
+  str_2 = str_0;
+  test_value(str_2.compare(str_0), z);
+  str_2 = L"cost";
+  test_value(str_2.compare(str_0), lt);
+  str_2 = L"costa ricans";
+  test_value(str_2.compare(str_0), gt);
+
+  // int compare(size_type pos1, size_type n1, const basic_string_view& str) const;
+  test_value(str_1.compare(0, 6, str_0), lt);
+  str_2 = L"cost";
+  test_value(str_1.compare(0, 4, str_2), z);
+  test_value(str_1.compare(0, 5, str_2), gt);
+
+  // int compare(size_type pos1, size_type n1, const basic_string_view& str,
+  //		 size_type pos2, size_type n2) const;
+  test_value(str_1.compare(0, 6, str_0, 0, 6), z);
+  test_value(str_1.compare(0, 7, str_0, 0, 7), lt);
+  test_value(str_0.compare(0, 7, str_1, 0, 7), gt);
+
+  // int compare(const charT* s) const;
+  test_value(str_0.compare(L"costa marbella"), gt);
+  test_value(str_1.compare(L"costa rica"), lt);
+  str_2 = str_0;
+  test_value(str_2.compare(L"costa rica"), z);
+  test_value(str_2.compare(L"cost"), gt);
+  test_value(str_2.compare(L"costa ricans"), lt);
+
+  // int compare(size_type pos, size_type n1, const charT* str,
+  //             size_type n2 = npos) const;
+  test_value(str_1.compare(0, 6, L"costa rica", 0, 6), z);
+  test_value(str_1.compare(0, 7, L"costa rica", 0, 7), lt);
+  test_value(str_0.compare(0, 7, L"costa marbella", 0, 7), gt);
+
+  return 0;
+}
+
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/compare/wchar_t/13650.cc b/gdb/unittests/basic_string_view/operations/compare/wchar_t/13650.cc
new file mode 100644
index 000000000000..dd19eb80665e
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/wchar_t/13650.cc
@@ -0,0 +1,49 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::compare [lib.string_view::compare]
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// libstdc++/13650
+void
+test01()
+{
+  using std::wstring_view;
+
+  const wchar_t lit_01[] = { L'w', L'e', L'\0', L'r', L'd' };
+  const wchar_t lit_02[] = { L'w', L'e', L'i', L'\0', L'd' };
+
+  const wchar_t lit_ref_a[] = { L'w', L'e', L'\0', L'q', L'd' };
+  const wstring_view str_a(lit_ref_a, 5);
+  VERIFY( str_a.compare(0, 5, lit_01, 5) < 0 );
+
+  const wchar_t lit_ref_b[] = { L'w', L'e', L'i' };
+  const wstring_view str_b(lit_ref_b, 3);
+  VERIFY( str_b.compare(0, 3, lit_02, 5) < 0 );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/compare/wchar_t/2.cc b/gdb/unittests/basic_string_view/operations/compare/wchar_t/2.cc
new file mode 100644
index 000000000000..250129c6c67a
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/compare/wchar_t/2.cc
@@ -0,0 +1,30 @@ 
+// Copyright (C) 2017-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <string_view>
+
+constexpr wchar_t c1[] = L"one";
+constexpr wchar_t c2[] = L"two";
+
+constexpr std::wstring_view s1{c1};
+constexpr std::wstring_view s2{c2};
+
+constexpr int n1 = s1.compare(s1);
+constexpr int n2 = s1.compare(s2);
diff --git a/gdb/unittests/basic_string_view/operations/copy/char/1.cc b/gdb/unittests/basic_string_view/operations/copy/char/1.cc
new file mode 100644
index 000000000000..6caf0e1507a6
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/copy/char/1.cc
@@ -0,0 +1,45 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::copy
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+
+  const char str_lit01[] = "123456789A";
+  const std::string_view str01(str_lit01);
+  char buffer[4] = { 0 };
+
+  csize_type len = str01.copy(buffer, sizeof(buffer), 8);
+  VERIFY( 2 == len );
+  VERIFY( '9' == buffer[0] );
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/copy/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/copy/wchar_t/1.cc
new file mode 100644
index 000000000000..84f3208add62
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/copy/wchar_t/1.cc
@@ -0,0 +1,46 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::copy
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type csz01;
+
+  const wchar_t str_lit01[] = L"123456789A";
+  const std::wstring_view str01(str_lit01);
+  wchar_t buffer[4] = { 0 };
+
+  csize_type len = str01.copy(buffer, sizeof(buffer), 8);
+  VERIFY( 2 == len );
+  VERIFY( L'9' == buffer[0] );
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/data/char/1.cc b/gdb/unittests/basic_string_view/operations/data/char/1.cc
new file mode 100644
index 000000000000..18fc9f5fe888
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/data/char/1.cc
@@ -0,0 +1,43 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// string_view operations
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+int
+test01()
+{
+  std::string_view empty;
+
+  VERIFY( empty.size() == 0 );
+  const std::string_view::value_type* p = empty.data();
+  VERIFY( p == nullptr );
+
+  return 0;
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/data/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/data/wchar_t/1.cc
new file mode 100644
index 000000000000..6596db528996
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/data/wchar_t/1.cc
@@ -0,0 +1,43 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2014 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// string_view operations
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+int
+test01()
+{
+  std::wstring_view empty;
+
+  VERIFY( empty.size() == 0 );
+  const std::wstring_view::value_type* p = empty.data();
+  VERIFY( p == nullptr );
+
+  return 0;
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/char/1.cc b/gdb/unittests/basic_string_view/operations/find/char/1.cc
new file mode 100644
index 000000000000..d7d2f37706eb
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/char/1.cc
@@ -0,0 +1,164 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01, csz02;
+
+  const char str_lit01[] = "mave";
+  const std::string_view str01("mavericks, santa cruz");
+  std::string_view str02(str_lit01);
+  std::string_view str03("s, s");
+  std::string_view str04;
+
+  // size_type find(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str01, 4);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str02, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 12);
+  VERIFY( csz01 == npos );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.find(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.find(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.find(str04, str01.size()+1);
+  VERIFY( csz01 == npos );
+
+  // size_type find(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type find(const char* s, size_type pos = 0) const;
+  csz01 = str01.find(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3);
+  VERIFY( csz01 == npos );
+
+  // size_type find(char c, size_type pos = 0) const;
+  csz01 = str01.find('z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.find('/');
+  VERIFY( csz01 == npos );
+}
+
+constexpr bool
+test02()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01 = 0, csz02 = 0;
+
+  const char str_lit01[] = "mave";
+  const std::string_view str01("mavericks, santa cruz");
+  std::string_view str02(str_lit01);
+  std::string_view str03("s, s");
+  std::string_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str01, 4);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str02, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 12);
+  VERIFY( csz01 == npos );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.find(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.find(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.find(str04, str01.size()+1);
+  VERIFY( csz01 == npos );
+
+  // size_type find(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type find(const char* s, size_type pos = 0) const;
+  csz01 = str01.find(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3);
+  VERIFY( csz01 == npos );
+
+  // size_type find(char c, size_type pos = 0) const;
+  csz01 = str01.find('z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.find('/');
+  VERIFY( csz01 == npos );
+
+  return true;
+}
+
+
+int
+main()
+{
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/char/2.cc b/gdb/unittests/basic_string_view/operations/find/char/2.cc
new file mode 100644
index 000000000000..af8a526d12c7
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/char/2.cc
@@ -0,0 +1,161 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find_first_of
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test02()
+{
+  typedef std::string_view::size_type csize_type;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01, csz02;
+
+  const char str_lit01[] = "mave";
+  const std::string_view str01("mavericks, santa cruz");
+  std::string_view str02(str_lit01);
+  std::string_view str03("s, s");
+  std::string_view str04;
+
+  // size_type find_first_of(const string_view&, size_type pos = 0) const;
+  std::string_view str05("xena rulez");
+  csz01 = str01.find_first_of(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str01, 4);
+  VERIFY( csz01 == 4 );
+  csz01 = str01.find_first_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str02, 3);
+  VERIFY( csz01 == 3 );
+  csz01 = str01.find_first_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 12);
+  VERIFY( csz01 == 16 );
+  csz01 = str01.find_first_of(str05, 0);
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_of(str05, 4);
+  VERIFY( csz01 == 4 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  // However, str1.find_first_of(str2,pos) finds the first character in
+  // str1 (starting at pos) that exists in str2, which is none for empty str2
+  csz01 = str01.find_first_of(str04, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_of(str04, 5);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_of(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_of(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3);
+  VERIFY( csz01 == 3 );
+
+  // size_type find_first_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_of('z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+}
+
+constexpr bool
+test03()
+{
+  typedef std::string_view::size_type csize_type;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01 = 0, csz02 = 0;
+
+  const char str_lit01[] = "mave";
+  const std::string_view str01("mavericks, santa cruz");
+  std::string_view str02(str_lit01);
+  std::string_view str03("s, s");
+  std::string_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find_first_of(const string_view&, size_type pos = 0) const;
+  std::string_view str05("xena rulez");
+  csz01 = str01.find_first_of(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str01, 4);
+  VERIFY( csz01 == 4 );
+  csz01 = str01.find_first_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str02, 3);
+  VERIFY( csz01 == 3 );
+  csz01 = str01.find_first_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 12);
+  VERIFY( csz01 == 16 );
+  csz01 = str01.find_first_of(str05, 0);
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_of(str05, 4);
+  VERIFY( csz01 == 4 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  // However, str1.find_first_of(str2,pos) finds the first character in
+  // str1 (starting at pos) that exists in str2, which is none for empty str2
+  csz01 = str01.find_first_of(str04, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_of(str04, 5);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_of(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_of(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3);
+  VERIFY( csz01 == 3 );
+
+  // size_type find_first_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_of('z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+
+  return true;
+}
+
+int
+main()
+{
+  test02();
+  static_assert( test03() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/char/3.cc b/gdb/unittests/basic_string_view/operations/find/char/3.cc
new file mode 100644
index 000000000000..5ec651ef3f93
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/char/3.cc
@@ -0,0 +1,161 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find_first_not_of
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test03()
+{
+  typedef std::string_view::size_type csize_type;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01;
+
+  const std::string_view str01("Bob Rock, per me");
+  const char str_lit01[] = "Bob Rock";
+  std::string_view str02("ovvero Trivi");
+  std::string_view str03(str_lit01);
+  std::string_view str04;
+
+  // size_type find_first_not_of(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str01);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str02, 10);
+  VERIFY( csz01 == 10 );
+  csz01 = str01.find_first_not_of(str02, 12);
+  VERIFY( csz01 == 14 );
+  csz01 = str01.find_first_not_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str03, 15);
+  VERIFY( csz01 == 15 );
+  csz01 = str01.find_first_not_of(str03, 16);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str04, 12);
+  VERIFY( csz01 == 12 );
+  csz01 = str03.find_first_not_of(str01, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str04.find_first_not_of(str02, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_not_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_not_of(str_lit01, 0, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str_lit01, 0, 8);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str_lit01, 10, 0);
+  VERIFY( csz01 == 10 );
+
+  // size_type find_first_not_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str_lit01);
+  VERIFY( csz01 == 8 );
+  csz01 = str02.find_first_not_of(str_lit01, 2);
+  VERIFY( csz01 == 2 );
+
+  // size_type find_first_not_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of('B');
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_not_of('o', 1);
+  VERIFY( csz01 == 2 );
+  csz01 = str02.find_first_not_of('z');
+  VERIFY( csz01 == 0 );
+  csz01 = str04.find_first_not_of('S');
+  VERIFY( csz01 == npos );
+}
+
+constexpr bool
+test04()
+{
+  typedef std::string_view::size_type csize_type;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01 = 0;
+
+  const std::string_view str01("Bob Rock, per me");
+  const char str_lit01[] = "Bob Rock";
+  std::string_view str02("ovvero Trivi");
+  std::string_view str03(str_lit01);
+  std::string_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find_first_not_of(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str01);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str02, 10);
+  VERIFY( csz01 == 10 );
+  csz01 = str01.find_first_not_of(str02, 12);
+  VERIFY( csz01 == 14 );
+  csz01 = str01.find_first_not_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str03, 15);
+  VERIFY( csz01 == 15 );
+  csz01 = str01.find_first_not_of(str03, 16);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str04, 12);
+  VERIFY( csz01 == 12 );
+  csz01 = str03.find_first_not_of(str01, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str04.find_first_not_of(str02, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_not_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_not_of(str_lit01, 0, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str_lit01, 0, 8);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str_lit01, 10, 0);
+  VERIFY( csz01 == 10 );
+
+  // size_type find_first_not_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str_lit01);
+  VERIFY( csz01 == 8 );
+  csz01 = str02.find_first_not_of(str_lit01, 2);
+  VERIFY( csz01 == 2 );
+
+  // size_type find_first_not_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of('B');
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_not_of('o', 1);
+  VERIFY( csz01 == 2 );
+  csz01 = str02.find_first_not_of('z');
+  VERIFY( csz01 == 0 );
+  csz01 = str04.find_first_not_of('S');
+  VERIFY( csz01 == npos );
+
+  return true;
+}
+
+int
+main()
+{
+  test03();
+  static_assert( test04() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/char/4.cc b/gdb/unittests/basic_string_view/operations/find/char/4.cc
new file mode 100644
index 000000000000..ca4b1f17db42
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/char/4.cc
@@ -0,0 +1,44 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// libstdc++/31401
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  csize_type npos = std::string_view::npos;
+
+  std::string_view use = "anu";
+  csize_type pos1 = use.find("a", npos);
+
+  VERIFY( pos1 == npos );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/find/wchar_t/1.cc
new file mode 100644
index 000000000000..535b2d5e383a
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/wchar_t/1.cc
@@ -0,0 +1,163 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01, csz02;
+
+  const wchar_t str_lit01[] = L"mave";
+  const std::wstring_view str01(L"mavericks, santa cruz");
+  std::wstring_view str02(str_lit01);
+  std::wstring_view str03(L"s, s");
+  std::wstring_view str04;
+
+  // size_type find(const wstring_view&, size_type pos = 0) const;
+  csz01 = str01.find(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str01, 4);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str02, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 12);
+  VERIFY( csz01 == npos );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.find(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.find(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.find(str04, str01.size()+1);
+  VERIFY( csz01 == npos );
+
+  // size_type find(const wchar_t* s, size_type pos, size_type n) const;
+  csz01 = str01.find(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type find(const wchar_t* s, size_type pos = 0) const;
+  csz01 = str01.find(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3);
+  VERIFY( csz01 == npos );
+
+  // size_type find(wchar_t c, size_type pos = 0) const;
+  csz01 = str01.find(L'z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.find(L'/');
+  VERIFY( csz01 == npos );
+}
+
+constexpr bool
+test02()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01 = 0, csz02 = 0;
+
+  const wchar_t str_lit01[] = L"mave";
+  const std::wstring_view str01(L"mavericks, santa cruz");
+  std::wstring_view str02(str_lit01);
+  std::wstring_view str03(L"s, s");
+  std::wstring_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find(const wstring_view&, size_type pos = 0) const;
+  csz01 = str01.find(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str01, 4);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str02, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find(str03, 12);
+  VERIFY( csz01 == npos );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.find(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.find(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.find(str04, str01.size()+1);
+  VERIFY( csz01 == npos );
+
+  // size_type find(const wchar_t* s, size_type pos, size_type n) const;
+  csz01 = str01.find(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type find(const wchar_t* s, size_type pos = 0) const;
+  csz01 = str01.find(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find(str_lit01, 3);
+  VERIFY( csz01 == npos );
+
+  // size_type find(wchar_t c, size_type pos = 0) const;
+  csz01 = str01.find(L'z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.find(L'/');
+  VERIFY( csz01 == npos );
+
+  return true;
+}
+
+int
+main()
+{
+  test01();
+  static_assert( test02() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/wchar_t/2.cc b/gdb/unittests/basic_string_view/operations/find/wchar_t/2.cc
new file mode 100644
index 000000000000..2802bf4442cb
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/wchar_t/2.cc
@@ -0,0 +1,161 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find_first_of
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test02()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01, csz02;
+
+  const wchar_t str_lit01[] = L"mave";
+  const std::wstring_view str01(L"mavericks, santa cruz");
+  std::wstring_view str02(str_lit01);
+  std::wstring_view str03(L"s, s");
+  std::wstring_view str04;
+
+  // size_type find_first_of(const wstring_view&, size_type pos = 0) const;
+  std::wstring_view str05(L"xena rulez");
+  csz01 = str01.find_first_of(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str01, 4);
+  VERIFY( csz01 == 4 );
+  csz01 = str01.find_first_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str02, 3);
+  VERIFY( csz01 == 3 );
+  csz01 = str01.find_first_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 12);
+  VERIFY( csz01 == 16 );
+  csz01 = str01.find_first_of(str05, 0);
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_of(str05, 4);
+  VERIFY( csz01 == 4 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  // However, str1.find_first_of(str2,pos) finds the first character in
+  // str1 (starting at pos) that exists in str2, which is none for empty str2
+  csz01 = str01.find_first_of(str04, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_of(str04, 5);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const wchar_t* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_of(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const wchar_t* s, size_type pos = 0) const;
+  csz01 = str01.find_first_of(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3);
+  VERIFY( csz01 == 3 );
+
+  // size_type find_first_of(wchar_t c, size_type pos = 0) const;
+  csz01 = str01.find_first_of(L'z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+}
+
+constexpr bool
+test04()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01 = 0, csz02 = 0;
+
+  const wchar_t str_lit01[] = L"mave";
+  const std::wstring_view str01(L"mavericks, santa cruz");
+  std::wstring_view str02(str_lit01);
+  std::wstring_view str03(L"s, s");
+  std::wstring_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find_first_of(const wstring_view&, size_type pos = 0) const;
+  std::wstring_view str05(L"xena rulez");
+  csz01 = str01.find_first_of(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str01, 4);
+  VERIFY( csz01 == 4 );
+  csz01 = str01.find_first_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str02, 3);
+  VERIFY( csz01 == 3 );
+  csz01 = str01.find_first_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 3);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_of(str03, 12);
+  VERIFY( csz01 == 16 );
+  csz01 = str01.find_first_of(str05, 0);
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_of(str05, 4);
+  VERIFY( csz01 == 4 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  // However, str1.find_first_of(str2,pos) finds the first character in
+  // str1 (starting at pos) that exists in str2, which is none for empty str2
+  csz01 = str01.find_first_of(str04, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_of(str04, 5);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const wchar_t* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_of(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_of(const wchar_t* s, size_type pos = 0) const;
+  csz01 = str01.find_first_of(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_of(str_lit01, 3);
+  VERIFY( csz01 == 3 );
+
+  // size_type find_first_of(wchar_t c, size_type pos = 0) const;
+  csz01 = str01.find_first_of(L'z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+
+  return true;
+}
+
+int
+main()
+{
+  test02();
+  static_assert( test04() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/wchar_t/3.cc b/gdb/unittests/basic_string_view/operations/find/wchar_t/3.cc
new file mode 100644
index 000000000000..6623bbdfc39f
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/wchar_t/3.cc
@@ -0,0 +1,161 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find_first_not_of
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test03()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01;
+
+  const std::wstring_view str01(L"Bob Rock, per me");
+  const wchar_t str_lit01[] = L"Bob Rock";
+  std::wstring_view str02(L"ovvero Trivi");
+  std::wstring_view str03(str_lit01);
+  std::wstring_view str04;
+
+  // size_type find_first_not_of(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str01);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str02, 10);
+  VERIFY( csz01 == 10 );
+  csz01 = str01.find_first_not_of(str02, 12);
+  VERIFY( csz01 == 14 );
+  csz01 = str01.find_first_not_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str03, 15);
+  VERIFY( csz01 == 15 );
+  csz01 = str01.find_first_not_of(str03, 16);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str04, 12);
+  VERIFY( csz01 == 12 );
+  csz01 = str03.find_first_not_of(str01, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str04.find_first_not_of(str02, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_not_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_not_of(str_lit01, 0, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str_lit01, 0, 8);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str_lit01, 10, 0);
+  VERIFY( csz01 == 10 );
+
+  // size_type find_first_not_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str_lit01);
+  VERIFY( csz01 == 8 );
+  csz01 = str02.find_first_not_of(str_lit01, 2);
+  VERIFY( csz01 == 2 );
+
+  // size_type find_first_not_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(L'B');
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_not_of(L'o', 1);
+  VERIFY( csz01 == 2 );
+  csz01 = str02.find_first_not_of(L'z');
+  VERIFY( csz01 == 0 );
+  csz01 = str04.find_first_not_of(L'S');
+  VERIFY( csz01 == npos );
+}
+
+constexpr bool
+test04()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01 = 0;
+
+  const std::wstring_view str01(L"Bob Rock, per me");
+  const wchar_t str_lit01[] = L"Bob Rock";
+  std::wstring_view str02(L"ovvero Trivi");
+  std::wstring_view str03(str_lit01);
+  std::wstring_view str04;
+
+#undef VERIFY
+#define VERIFY(x) if(!(x)) return false
+
+  // size_type find_first_not_of(const string_view&, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str01);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str02, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str02, 10);
+  VERIFY( csz01 == 10 );
+  csz01 = str01.find_first_not_of(str02, 12);
+  VERIFY( csz01 == 14 );
+  csz01 = str01.find_first_not_of(str03, 0);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str03, 15);
+  VERIFY( csz01 == 15 );
+  csz01 = str01.find_first_not_of(str03, 16);
+  VERIFY( csz01 == npos );
+  csz01 = str01.find_first_not_of(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str04, 12);
+  VERIFY( csz01 == 12 );
+  csz01 = str03.find_first_not_of(str01, 0);
+  VERIFY( csz01 == npos );
+  csz01 = str04.find_first_not_of(str02, 0);
+  VERIFY( csz01 == npos );
+
+  // size_type find_first_not_of(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.find_first_not_of(str_lit01, 0, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.find_first_not_of(str_lit01, 0, 8);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.find_first_not_of(str_lit01, 10, 0);
+  VERIFY( csz01 == 10 );
+
+  // size_type find_first_not_of(const char* s, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(str_lit01);
+  VERIFY( csz01 == 8 );
+  csz01 = str02.find_first_not_of(str_lit01, 2);
+  VERIFY( csz01 == 2 );
+
+  // size_type find_first_not_of(char c, size_type pos = 0) const;
+  csz01 = str01.find_first_not_of(L'B');
+  VERIFY( csz01 == 1 );
+  csz01 = str01.find_first_not_of(L'o', 1);
+  VERIFY( csz01 == 2 );
+  csz01 = str02.find_first_not_of(L'z');
+  VERIFY( csz01 == 0 );
+  csz01 = str04.find_first_not_of(L'S');
+  VERIFY( csz01 == npos );
+
+  return true;
+}
+
+int
+main()
+{
+  test03();
+  static_assert( test04() );
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/find/wchar_t/4.cc b/gdb/unittests/basic_string_view/operations/find/wchar_t/4.cc
new file mode 100644
index 000000000000..213bf78cf937
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/find/wchar_t/4.cc
@@ -0,0 +1,44 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view find
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// libstdc++/31401
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  csize_type npos = std::wstring_view::npos;
+
+  std::wstring_view use = L"anu";
+  csize_type pos1 = use.find(L"a", npos);
+
+  VERIFY( pos1 == npos );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/char/1.cc b/gdb/unittests/basic_string_view/operations/rfind/char/1.cc
new file mode 100644
index 000000000000..ef26688fd761
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/char/1.cc
@@ -0,0 +1,94 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view rfind
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+  csize_type npos = std::string_view::npos;
+  csize_type csz01, csz02;
+
+  const char str_lit01[] = "mave";
+  const std::string_view str01("mavericks, santa cruz");
+  std::string_view str02(str_lit01);
+  std::string_view str03("s, s");
+  std::string_view str04;
+
+  // size_type rfind(const string_view&, size_type pos = 0) const;
+  csz01 = str01.rfind(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str01, 4);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str02,3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str02);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str03);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.rfind(str03, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.rfind(str03, 12);
+  VERIFY( csz01 == 8 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.rfind(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.rfind(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.rfind(str04, str01.size()+1);
+  VERIFY( csz01 == str01.size() );
+
+  // size_type rfind(const char* s, size_type pos, size_type n) const;
+  csz01 = str01.rfind(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type rfind(const char* s, size_type pos = 0) const;
+  csz01 = str01.rfind(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str_lit01, 3);
+  VERIFY( csz01 == 0 );
+
+  // size_type rfind(char c, size_type pos = 0) const;
+  csz01 = str01.rfind('z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.rfind('/');
+  VERIFY( csz01 == npos );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/char/2.cc b/gdb/unittests/basic_string_view/operations/rfind/char/2.cc
new file mode 100644
index 000000000000..df37f8c7745b
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/char/2.cc
@@ -0,0 +1,52 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view::find_last_of
+
+void
+test02()
+{
+  std::string_view z("ab");
+  std::string_view::size_type pos;
+  pos = z.find_last_of("ab");
+  VERIFY( pos == 1 );
+  pos = z.find_last_of("Xa");
+  VERIFY( pos == 0 );
+  pos = z.find_last_of("Xb");
+  VERIFY( pos == 1 );
+  pos = z.find_last_of("XYZ");
+  VERIFY( pos == std::string_view::npos );
+  pos = z.find_last_of('a');
+  VERIFY( pos == 0 );
+  pos = z.find_last_of('b');
+  VERIFY( pos == 1 );
+  pos = z.find_last_of('X');
+  VERIFY( pos == std::string_view::npos );
+}
+
+int
+main()
+{
+  test02();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/char/3.cc b/gdb/unittests/basic_string_view/operations/rfind/char/3.cc
new file mode 100644
index 000000000000..37f01a28af7f
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/char/3.cc
@@ -0,0 +1,66 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view::find_last_not_of
+
+void
+test03()
+{
+  typedef std::string_view::size_type csize_type;
+  std::string_view::size_type pos;
+  csize_type npos = std::string_view::npos;
+
+  std::string_view x;
+  pos = x.find_last_not_of('X');
+  VERIFY( pos == npos );
+  pos = x.find_last_not_of("XYZ");
+  VERIFY( pos == npos );
+
+  std::string_view y("a");
+  pos = y.find_last_not_of('X');
+  VERIFY( pos == 0 );
+  pos = y.find_last_not_of('a');
+  VERIFY( pos == npos );
+  pos = y.find_last_not_of("XYZ");
+  VERIFY( pos == 0 );
+  pos = y.find_last_not_of("a");
+  VERIFY( pos == npos );
+
+  std::string_view z("ab");
+  pos = z.find_last_not_of('X');
+  VERIFY( pos == 1 );
+  pos = z.find_last_not_of("XYZ");
+  VERIFY( pos == 1 );
+  pos = z.find_last_not_of('b');
+  VERIFY( pos == 0 );
+  pos = z.find_last_not_of("Xb");
+  VERIFY( pos == 0 );
+  pos = z.find_last_not_of("Xa");
+  VERIFY( pos == 1 );
+}
+int
+main()
+{
+  test03();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/1.cc
new file mode 100644
index 000000000000..197515f9b6cc
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/1.cc
@@ -0,0 +1,94 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view rfind
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type npos = std::wstring_view::npos;
+  csize_type csz01, csz02;
+
+  const wchar_t str_lit01[] = L"mave";
+  const std::wstring_view str01(L"mavericks, santa cruz");
+  std::wstring_view str02(str_lit01);
+  std::wstring_view str03(L"s, s");
+  std::wstring_view str04;
+
+  // size_type rfind(const wstring_view&, size_type pos = 0) const;
+  csz01 = str01.rfind(str01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str01, 4);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str02,3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str02);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str03);
+  VERIFY( csz01 == 8 );
+  csz01 = str01.rfind(str03, 3);
+  VERIFY( csz01 == npos );
+  csz01 = str01.rfind(str03, 12);
+  VERIFY( csz01 == 8 );
+
+  // An empty string_view consists of no characters
+  // therefore it should be found at every point in a string_view,
+  // except beyond the end
+  csz01 = str01.rfind(str04, 0);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str04, 5);
+  VERIFY( csz01 == 5 );
+  csz01 = str01.rfind(str04, str01.size());
+  VERIFY( csz01 == str01.size() );
+  csz01 = str01.rfind(str04, str01.size()+1);
+  VERIFY( csz01 == str01.size() );
+
+  // size_type rfind(const wchar_t* s, size_type pos, size_type n) const;
+  csz01 = str01.rfind(str_lit01, 0, 3);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str_lit01, 3, 0);
+  VERIFY( csz01 == 3 );
+
+  // size_type rfind(const wchar_t* s, size_type pos = 0) const;
+  csz01 = str01.rfind(str_lit01);
+  VERIFY( csz01 == 0 );
+  csz01 = str01.rfind(str_lit01, 3);
+  VERIFY( csz01 == 0 );
+
+  // size_type rfind(wchar_t c, size_type pos = 0) const;
+  csz01 = str01.rfind(L'z');
+  csz02 = str01.size() - 1;
+  VERIFY( csz01 == csz02 );
+  csz01 = str01.rfind(L'/');
+  VERIFY( csz01 == npos );
+}
+
+int
+main()
+{
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/wchar_t/2.cc b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/2.cc
new file mode 100644
index 000000000000..7fb7c6c328bb
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/2.cc
@@ -0,0 +1,52 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view::find_last_of
+
+void
+test02()
+{
+  std::wstring_view::size_type pos;
+  std::wstring_view z(L"ab");
+  pos = z.find_last_of(L"ab");
+  VERIFY( pos == 1 );
+  pos = z.find_last_of(L"Xa");
+  VERIFY( pos == 0 );
+  pos = z.find_last_of(L"Xb");
+  VERIFY( pos == 1 );
+  pos = z.find_last_of(L"XYZ");
+  VERIFY( pos == std::wstring_view::npos );
+  pos = z.find_last_of(L'a');
+  VERIFY( pos == 0 );
+  pos = z.find_last_of(L'b');
+  VERIFY( pos == 1 );
+  pos = z.find_last_of(L'X');
+  VERIFY( pos == std::wstring_view::npos );
+}
+
+int
+main()
+{
+  test02();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/rfind/wchar_t/3.cc b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/3.cc
new file mode 100644
index 000000000000..ad34cd3df7cf
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/rfind/wchar_t/3.cc
@@ -0,0 +1,66 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+// basic_string_view::find_last_not_of
+
+void
+test03()
+{
+  typedef std::wstring_view::size_type csize_type;
+  std::wstring_view::size_type pos;
+  csize_type npos = std::wstring_view::npos;
+
+  std::wstring_view x;
+  pos = x.find_last_not_of(L'X');
+  VERIFY( pos == npos );
+  pos = x.find_last_not_of(L"XYZ");
+  VERIFY( pos == npos );
+
+  std::wstring_view y(L"a");
+  pos = y.find_last_not_of(L'X');
+  VERIFY( pos == 0 );
+  pos = y.find_last_not_of(L'a');
+  VERIFY( pos == npos );
+  pos = y.find_last_not_of(L"XYZ");
+  VERIFY( pos == 0 );
+  pos = y.find_last_not_of(L"a");
+  VERIFY( pos == npos );
+
+  std::wstring_view z(L"ab");
+  pos = z.find_last_not_of(L'X');
+  VERIFY( pos == 1 );
+  pos = z.find_last_not_of(L"XYZ");
+  VERIFY( pos == 1 );
+  pos = z.find_last_not_of(L'b');
+  VERIFY( pos == 0 );
+  pos = z.find_last_not_of(L"Xb");
+  VERIFY( pos == 0 );
+  pos = z.find_last_not_of(L"Xa");
+  VERIFY( pos == 1 );
+}
+int
+main()
+{
+  test03();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/string_conversion/1.cc b/gdb/unittests/basic_string_view/operations/string_conversion/1.cc
new file mode 100644
index 000000000000..c6bfa0b79fe2
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/string_conversion/1.cc
@@ -0,0 +1,51 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2014-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::to_string
+
+#include <string_view>
+#include <string>
+#include <algorithm>
+#include <testsuite_hooks.h>
+#include <testsuite_allocator.h>
+
+void
+test01()
+{
+  const char str_lit[] = "123456789A";
+  const std::string_view sv(str_lit);
+  char buffer[4] = { 0 };
+
+  std::string s1{sv};
+  VERIFY( s1 == str_lit );
+  using test_alloc = __gnu_test::tracker_allocator<char>;
+  std::basic_string<char, std::char_traits<char>, test_alloc>
+    s2{sv, test_alloc{}};
+  static_assert( std::is_same<decltype(s2)::allocator_type, test_alloc>::value,
+                 "to_string() uses custom allocator" );
+  VERIFY( std::equal(s1.begin(), s1.end(), s2.begin(), s2.end()) );
+  auto s3 = static_cast<std::string>(sv);
+  VERIFY( s3 == s1 );
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/gdb/unittests/basic_string_view/operations/substr/char/1.cc b/gdb/unittests/basic_string_view/operations/substr/char/1.cc
new file mode 100644
index 000000000000..ac65c23c54be
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/substr/char/1.cc
@@ -0,0 +1,79 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::substr
+
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::string_view::size_type csize_type;
+  typedef std::string_view::const_reference cref;
+  typedef std::string_view::reference ref;
+  csize_type csz01;
+
+  const char str_lit01[] = "rockaway, pacifica";
+  const std::string_view str01(str_lit01);
+  std::string_view str02;
+
+  // basic_string_view<charT, _Traits, _Alloc>
+  //  substr(size_type pos = 0, size_type n = npos) const;
+  csz01 = str01.size();
+  str02 = str01.substr(0, 1);
+  VERIFY( str02 == "r" );
+  str02 = str01.substr(10);
+  VERIFY( str02 == "pacifica" );
+
+  try
+  {
+    str02 = str01.substr(csz01 + 1);
+    VERIFY( false ); 
+  }
+  catch(std::out_of_range& fail)
+  {
+    VERIFY( true );
+  }
+  catch(...)
+  {
+    VERIFY( false );
+  }
+
+  try
+  {
+    str02 = str01.substr(csz01);
+    VERIFY( str02.size() == 0 );
+    VERIFY( str02.begin() == str01.end() );
+    VERIFY( true );
+  }
+  catch(...)
+  {
+    VERIFY( false );
+  }
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operations/substr/wchar_t/1.cc b/gdb/unittests/basic_string_view/operations/substr/wchar_t/1.cc
new file mode 100644
index 000000000000..eb19ece2e79a
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operations/substr/wchar_t/1.cc
@@ -0,0 +1,79 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view::substr
+
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type csz01;
+
+  const wchar_t str_lit01[] = L"rockaway, pacifica";
+  const std::wstring_view str01(str_lit01);
+  std::wstring_view str02;
+
+  // basic_string_view<charT, _Traits, _Alloc>
+  //  substr(size_type pos = 0, size_type n = npos) const;
+  csz01 = str01.size();
+  str02 = str01.substr(0, 1);
+  VERIFY( str02 == L"r" );
+  str02 = str01.substr(10);
+  VERIFY( str02 == L"pacifica" );
+
+  try
+  {
+    str02 = str01.substr(csz01 + 1);
+    VERIFY( false ); 
+  }
+  catch(std::out_of_range& fail)
+  {
+    VERIFY( true );
+  }
+  catch(...)
+  {
+    VERIFY( false );
+  }
+
+  try
+  {
+    str02 = str01.substr(csz01);
+    VERIFY( str02.size() == 0 );
+    VERIFY( str02.begin() == str01.end() );
+    VERIFY( true );
+  }
+  catch(...)
+  {
+    VERIFY( false );
+  }
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}
diff --git a/gdb/unittests/basic_string_view/operators/char/2.cc b/gdb/unittests/basic_string_view/operators/char/2.cc
new file mode 100644
index 000000000000..4be652daafb2
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operators/char/2.cc
@@ -0,0 +1,367 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string non-member functions
+
+// operator==
+/*
+template<class charT, class traits, class Allocator>
+  bool operator==(const basic_string<charT,traits,Allocator>& lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator==(const charT* lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator==(const basic_string<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+*/
+
+// operator!=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator!=(const basic_string<charT,traits,Allocator>& lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator!=(const charT* lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator!=(const basic_string<charT,traits,Allocator>& lhs, 
+                  const charT* rhs);
+*/
+
+// operator<
+/*
+template<class charT, class traits, class Allocator>
+  bool operator< (const basic_string<charT,traits,Allocator>& lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator< (const basic_string<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator< (const charT* lhs, 
+                  const basic_string<charT,traits,Allocator>& rhs);
+*/
+
+// operator>
+/*
+template<class charT, class traits, class Allocator>
+  bool operator> (const basic_string<charT,traits,Allocator>& lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator> (const basic_string<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator> (const charT* lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+*/
+
+// operator<=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator<=(const basic_string<charT,traits,Allocator>& lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator<=(const basic_string<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator<=(const charT* lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+*/
+
+// operator>=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator>=(const basic_string<charT,traits,Allocator>& lhs,
+                const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator>=(const basic_string<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator>=(const charT* lhs,
+                  const basic_string<charT,traits,Allocator>& rhs);
+*/
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::string_view 	str_0("costa rica");
+  std::string_view 	str_1("costa marbella");
+  std::string_view 	str_2("cost");
+  std::string_view	str_3("costa ricans");
+  std::string_view        str_4;
+
+  str_4 = str_0;
+  //comparisons between string objects
+  VERIFY( !(str_0 == str_1) );
+  VERIFY( !(str_0 == str_2) );
+  VERIFY( !(str_0 == str_3) );
+  VERIFY( !(str_1 == str_0) );
+  VERIFY( !(str_2 == str_0) );
+  VERIFY( !(str_3 == str_0) );
+  VERIFY( str_4 == str_0 );
+  VERIFY( str_0 == str_4 );
+
+  VERIFY( str_0 != str_1 );
+  VERIFY( str_0 != str_2 );
+  VERIFY( str_0 != str_3 );
+  VERIFY( str_1 != str_0 );
+  VERIFY( str_2 != str_0 );
+  VERIFY( str_3 != str_0 );
+  VERIFY( !(str_0 != str_4) );
+  VERIFY( !(str_4 != str_0) );
+
+  VERIFY( str_0 > str_1 ); //true cuz r>m
+  VERIFY( str_0 > str_2 );
+  VERIFY( !(str_0 > str_3) );
+  VERIFY( !(str_1 > str_0) ); //false cuz m<r
+  VERIFY( !(str_2 > str_0) );
+  VERIFY( str_3 > str_0 );
+  VERIFY( !(str_0 > str_4) );
+  VERIFY( !(str_4 > str_0) );
+
+  VERIFY( !(str_0 < str_1) ); //false cuz r>m
+  VERIFY( !(str_0 < str_2) );
+  VERIFY( str_0 < str_3 );
+  VERIFY( str_1 < str_0 ); //true cuz m<r
+  VERIFY( str_2 < str_0 );
+  VERIFY( !(str_3 < str_0) );
+  VERIFY( !(str_0 < str_4) );
+  VERIFY( !(str_4 < str_0) );
+
+  VERIFY( str_0 >= str_1 ); //true cuz r>m
+  VERIFY( str_0 >= str_2 );
+  VERIFY( !(str_0 >= str_3) );
+  VERIFY( !(str_1 >= str_0) );//false cuz m<r
+  VERIFY( !(str_2 >= str_0) );
+  VERIFY( str_3 >= str_0 );
+  VERIFY( str_0 >= str_4 );
+  VERIFY( str_4 >= str_0 );
+
+  VERIFY( !(str_0 <= str_1) );//false cuz r>m
+  VERIFY( !(str_0 <= str_2) );
+  VERIFY( str_0 <= str_3 );
+  VERIFY( str_1 <= str_0 );//true cuz m<r
+  VERIFY( str_2 <= str_0 );
+  VERIFY( !(str_3 <= str_0) );
+  VERIFY( str_0 <= str_4 );
+  VERIFY( str_4 <= str_0 );
+
+  //comparisons between string object and string literal
+  VERIFY( !(str_0 == "costa marbella") );
+  VERIFY( !(str_0 == "cost") );
+  VERIFY( !(str_0 == "costa ricans") );
+  VERIFY( !("costa marbella" == str_0) );
+  VERIFY( !("cost" == str_0) );
+  VERIFY( !("costa ricans" == str_0) );
+  VERIFY( "costa rica" == str_0 );
+  VERIFY( str_0 == "costa rica" );
+
+  VERIFY( str_0 != "costa marbella" );
+  VERIFY( str_0 != "cost" );
+  VERIFY( str_0 != "costa ricans" );
+  VERIFY( "costa marbella" != str_0 );
+  VERIFY( "cost" != str_0 );
+  VERIFY( "costa ricans" != str_0 );
+  VERIFY( !("costa rica" != str_0) );
+  VERIFY( !(str_0 != "costa rica") );
+
+  VERIFY( str_0 > "costa marbella" ); //true cuz r>m
+  VERIFY( str_0 > "cost" );
+  VERIFY( !(str_0 > "costa ricans") );
+  VERIFY( !("costa marbella" > str_0) );//false cuz m<r
+  VERIFY( !("cost" > str_0) );
+  VERIFY( "costa ricans" > str_0 );
+  VERIFY( !("costa rica" > str_0) );
+  VERIFY( !(str_0 > "costa rica") );
+
+  VERIFY( !(str_0 < "costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 < "cost") );
+  VERIFY( str_0 < "costa ricans" );
+  VERIFY( "costa marbella" < str_0 );//true cuz m<r
+  VERIFY( "cost" < str_0 );
+  VERIFY( !("costa ricans" < str_0) );
+  VERIFY( !("costa rica" < str_0) );
+  VERIFY( !(str_0 < "costa rica") );
+
+  VERIFY( str_0 >= "costa marbella" );//true cuz r>m
+  VERIFY( str_0 >= "cost" );
+  VERIFY( !(str_0 >= "costa ricans") );
+  VERIFY( !("costa marbella" >= str_0) );//false cuz m<r
+  VERIFY( !("cost" >= str_0) );
+  VERIFY( "costa ricans" >= str_0 );
+  VERIFY( "costa rica" >= str_0 );
+  VERIFY( str_0 >= "costa rica" );
+
+  VERIFY( !(str_0 <= "costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 <= "cost") );
+  VERIFY( str_0 <= "costa ricans" );
+  VERIFY( "costa marbella" <= str_0 );//true cuz m<r
+  VERIFY( "cost" <= str_0 );
+  VERIFY( !("costa ricans" <= str_0) );
+  VERIFY( "costa rica" <= str_0 );
+  VERIFY( str_0 <= "costa rica" );
+}
+
+constexpr bool
+test02()
+{
+  std::string_view 	str_0("costa rica");
+  std::string_view 	str_1("costa marbella");
+  std::string_view 	str_2("cost");
+  std::string_view	str_3("costa ricans");
+  std::string_view        str_4;
+
+#undef VERIFY
+#define VERIFY(x) if (!(x)) return false
+
+  str_4 = str_0;
+  //comparisons between string objects
+  VERIFY( !(str_0 == str_1) );
+  VERIFY( !(str_0 == str_2) );
+  VERIFY( !(str_0 == str_3) );
+  VERIFY( !(str_1 == str_0) );
+  VERIFY( !(str_2 == str_0) );
+  VERIFY( !(str_3 == str_0) );
+  VERIFY( str_4 == str_0 );
+  VERIFY( str_0 == str_4 );
+
+  VERIFY( str_0 != str_1 );
+  VERIFY( str_0 != str_2 );
+  VERIFY( str_0 != str_3 );
+  VERIFY( str_1 != str_0 );
+  VERIFY( str_2 != str_0 );
+  VERIFY( str_3 != str_0 );
+  VERIFY( !(str_0 != str_4) );
+  VERIFY( !(str_4 != str_0) );
+
+  VERIFY( str_0 > str_1 ); //true cuz r>m
+  VERIFY( str_0 > str_2 );
+  VERIFY( !(str_0 > str_3) );
+  VERIFY( !(str_1 > str_0) ); //false cuz m<r
+  VERIFY( !(str_2 > str_0) );
+  VERIFY( str_3 > str_0 );
+  VERIFY( !(str_0 > str_4) );
+  VERIFY( !(str_4 > str_0) );
+
+  VERIFY( !(str_0 < str_1) ); //false cuz r>m
+  VERIFY( !(str_0 < str_2) );
+  VERIFY( str_0 < str_3 );
+  VERIFY( str_1 < str_0 ); //true cuz m<r
+  VERIFY( str_2 < str_0 );
+  VERIFY( !(str_3 < str_0) );
+  VERIFY( !(str_0 < str_4) );
+  VERIFY( !(str_4 < str_0) );
+
+  VERIFY( str_0 >= str_1 ); //true cuz r>m
+  VERIFY( str_0 >= str_2 );
+  VERIFY( !(str_0 >= str_3) );
+  VERIFY( !(str_1 >= str_0) );//false cuz m<r
+  VERIFY( !(str_2 >= str_0) );
+  VERIFY( str_3 >= str_0 );
+  VERIFY( str_0 >= str_4 );
+  VERIFY( str_4 >= str_0 );
+
+  VERIFY( !(str_0 <= str_1) );//false cuz r>m
+  VERIFY( !(str_0 <= str_2) );
+  VERIFY( str_0 <= str_3 );
+  VERIFY( str_1 <= str_0 );//true cuz m<r
+  VERIFY( str_2 <= str_0 );
+  VERIFY( !(str_3 <= str_0) );
+  VERIFY( str_0 <= str_4 );
+  VERIFY( str_4 <= str_0 );
+
+  //comparisons between string object and string literal
+  VERIFY( !(str_0 == "costa marbella") );
+  VERIFY( !(str_0 == "cost") );
+  VERIFY( !(str_0 == "costa ricans") );
+  VERIFY( !("costa marbella" == str_0) );
+  VERIFY( !("cost" == str_0) );
+  VERIFY( !("costa ricans" == str_0) );
+  VERIFY( "costa rica" == str_0 );
+  VERIFY( str_0 == "costa rica" );
+
+  VERIFY( str_0 != "costa marbella" );
+  VERIFY( str_0 != "cost" );
+  VERIFY( str_0 != "costa ricans" );
+  VERIFY( "costa marbella" != str_0 );
+  VERIFY( "cost" != str_0 );
+  VERIFY( "costa ricans" != str_0 );
+  VERIFY( !("costa rica" != str_0) );
+  VERIFY( !(str_0 != "costa rica") );
+
+  VERIFY( str_0 > "costa marbella" ); //true cuz r>m
+  VERIFY( str_0 > "cost" );
+  VERIFY( !(str_0 > "costa ricans") );
+  VERIFY( !("costa marbella" > str_0) );//false cuz m<r
+  VERIFY( !("cost" > str_0) );
+  VERIFY( "costa ricans" > str_0 );
+  VERIFY( !("costa rica" > str_0) );
+  VERIFY( !(str_0 > "costa rica") );
+
+  VERIFY( !(str_0 < "costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 < "cost") );
+  VERIFY( str_0 < "costa ricans" );
+  VERIFY( "costa marbella" < str_0 );//true cuz m<r
+  VERIFY( "cost" < str_0 );
+  VERIFY( !("costa ricans" < str_0) );
+  VERIFY( !("costa rica" < str_0) );
+  VERIFY( !(str_0 < "costa rica") );
+
+  VERIFY( str_0 >= "costa marbella" );//true cuz r>m
+  VERIFY( str_0 >= "cost" );
+  VERIFY( !(str_0 >= "costa ricans") );
+  VERIFY( !("costa marbella" >= str_0) );//false cuz m<r
+  VERIFY( !("cost" >= str_0) );
+  VERIFY( "costa ricans" >= str_0 );
+  VERIFY( "costa rica" >= str_0 );
+  VERIFY( str_0 >= "costa rica" );
+
+  VERIFY( !(str_0 <= "costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 <= "cost") );
+  VERIFY( str_0 <= "costa ricans" );
+  VERIFY( "costa marbella" <= str_0 );//true cuz m<r
+  VERIFY( "cost" <= str_0 );
+  VERIFY( !("costa ricans" <= str_0) );
+  VERIFY( "costa rica" <= str_0 );
+  VERIFY( str_0 <= "costa rica" );
+
+  return true;
+}
+
+int
+main()
+{
+  test01();
+  static_assert( test02() );
+}
diff --git a/gdb/unittests/basic_string_view/operators/wchar_t/2.cc b/gdb/unittests/basic_string_view/operators/wchar_t/2.cc
new file mode 100644
index 000000000000..f4088c85b0b1
--- /dev/null
+++ b/gdb/unittests/basic_string_view/operators/wchar_t/2.cc
@@ -0,0 +1,367 @@ 
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view non-member functions
+
+// operator==
+/*
+template<class charT, class traits, class Allocator>
+  bool operator==(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator==(const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator==(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+*/
+
+// operator!=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator!=(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator!=(const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator!=(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+*/
+
+// operator<
+/*
+template<class charT, class traits, class Allocator>
+  bool operator< (const basic_string_view<charT,traits,Allocator>& lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator< (const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator< (const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+*/
+
+// operator>
+/*
+template<class charT, class traits, class Allocator>
+  bool operator> (const basic_string_view<charT,traits,Allocator>& lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator> (const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator> (const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+*/
+
+// operator<=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator<=(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator<=(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator<=(const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+*/
+
+// operator>=
+/*
+template<class charT, class traits, class Allocator>
+  bool operator>=(const basic_string_view<charT,traits,Allocator>& lhs,
+                const basic_string_view<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator>=(const basic_string_view<charT,traits,Allocator>& lhs,
+                  const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  bool operator>=(const charT* lhs,
+                  const basic_string_view<charT,traits,Allocator>& rhs);
+*/
+
+#include <string_view>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::wstring_view 	str_0(L"costa rica");
+  std::wstring_view 	str_1(L"costa marbella");
+  std::wstring_view 	str_2(L"cost");
+  std::wstring_view	str_3(L"costa ricans");
+  std::wstring_view  str_4;
+
+  str_4 = str_0;
+  //comparisons between string_view objects
+  VERIFY( !(str_0 == str_1) );
+  VERIFY( !(str_0 == str_2) );
+  VERIFY( !(str_0 == str_3) );
+  VERIFY( !(str_1 == str_0) );
+  VERIFY( !(str_2 == str_0) );
+  VERIFY( !(str_3 == str_0) );
+  VERIFY( str_4 == str_0 );
+  VERIFY( str_0 == str_4 );
+
+  VERIFY( str_0 != str_1 );
+  VERIFY( str_0 != str_2 );
+  VERIFY( str_0 != str_3 );
+  VERIFY( str_1 != str_0 );
+  VERIFY( str_2 != str_0 );
+  VERIFY( str_3 != str_0 );
+  VERIFY( !(str_0 != str_4) );
+  VERIFY( !(str_4 != str_0) );
+
+  VERIFY( str_0 > str_1 ); //true cuz r>m
+  VERIFY( str_0 > str_2 );
+  VERIFY( !(str_0 > str_3) );
+  VERIFY( !(str_1 > str_0) ); //false cuz m<r
+  VERIFY( !(str_2 > str_0) );
+  VERIFY( str_3 > str_0 );
+  VERIFY( !(str_0 > str_4) );
+  VERIFY( !(str_4 > str_0) );
+
+  VERIFY( !(str_0 < str_1) ); //false cuz r>m
+  VERIFY( !(str_0 < str_2) );
+  VERIFY( str_0 < str_3 );
+  VERIFY( str_1 < str_0 ); //true cuz m<r
+  VERIFY( str_2 < str_0 );
+  VERIFY( !(str_3 < str_0) );
+  VERIFY( !(str_0 < str_4) );
+  VERIFY( !(str_4 < str_0) );
+
+  VERIFY( str_0 >= str_1 ); //true cuz r>m
+  VERIFY( str_0 >= str_2 );
+  VERIFY( !(str_0 >= str_3) );
+  VERIFY( !(str_1 >= str_0) );//false cuz m<r
+  VERIFY( !(str_2 >= str_0) );
+  VERIFY( str_3 >= str_0 );
+  VERIFY( str_0 >= str_4 );
+  VERIFY( str_4 >= str_0 );
+
+  VERIFY( !(str_0 <= str_1) );//false cuz r>m
+  VERIFY( !(str_0 <= str_2) );
+  VERIFY( str_0 <= str_3 );
+  VERIFY( str_1 <= str_0 );//true cuz m<r
+  VERIFY( str_2 <= str_0 );
+  VERIFY( !(str_3 <= str_0) );
+  VERIFY( str_0 <= str_4 );
+  VERIFY( str_4 <= str_0 );
+
+  //comparisons between string_view object and string_view literal
+  VERIFY( !(str_0 == L"costa marbella") );
+  VERIFY( !(str_0 == L"cost") );
+  VERIFY( !(str_0 == L"costa ricans") );
+  VERIFY( !(L"costa marbella" == str_0) );
+  VERIFY( !(L"cost" == str_0) );
+  VERIFY( !(L"costa ricans" == str_0) );
+  VERIFY( L"costa rica" == str_0 );
+  VERIFY( str_0 == L"costa rica" );
+
+  VERIFY( str_0 != L"costa marbella" );
+  VERIFY( str_0 != L"cost" );
+  VERIFY( str_0 != L"costa ricans" );
+  VERIFY( L"costa marbella" != str_0 );
+  VERIFY( L"cost" != str_0 );
+  VERIFY( L"costa ricans" != str_0 );
+  VERIFY( !(L"costa rica" != str_0) );
+  VERIFY( !(str_0 != L"costa rica") );
+
+  VERIFY( str_0 > L"costa marbella" ); //true cuz r>m
+  VERIFY( str_0 > L"cost" );
+  VERIFY( !(str_0 > L"costa ricans") );
+  VERIFY( !(L"costa marbella" > str_0) );//false cuz m<r
+  VERIFY( !(L"cost" > str_0) );
+  VERIFY( L"costa ricans" > str_0 );
+  VERIFY( !(L"costa rica" > str_0) );
+  VERIFY( !(str_0 > L"costa rica") );
+
+  VERIFY( !(str_0 < L"costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 < L"cost") );
+  VERIFY( str_0 < L"costa ricans" );
+  VERIFY( L"costa marbella" < str_0 );//true cuz m<r
+  VERIFY( L"cost" < str_0 );
+  VERIFY( !(L"costa ricans" < str_0) );
+  VERIFY( !(L"costa rica" < str_0) );
+  VERIFY( !(str_0 < L"costa rica") );
+
+  VERIFY( str_0 >= L"costa marbella" );//true cuz r>m
+  VERIFY( str_0 >= L"cost" );
+  VERIFY( !(str_0 >= L"costa ricans") );
+  VERIFY( !(L"costa marbella" >= str_0) );//false cuz m<r
+  VERIFY( !(L"cost" >= str_0) );
+  VERIFY( L"costa ricans" >= str_0 );
+  VERIFY( L"costa rica" >= str_0 );
+  VERIFY( str_0 >= L"costa rica" );
+
+  VERIFY( !(str_0 <= L"costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 <= L"cost") );
+  VERIFY( str_0 <= L"costa ricans" );
+  VERIFY( L"costa marbella" <= str_0 );//true cuz m<r
+  VERIFY( L"cost" <= str_0 );
+  VERIFY( !(L"costa ricans" <= str_0) );
+  VERIFY( L"costa rica" <= str_0 );
+  VERIFY( str_0 <= L"costa rica" );
+}
+
+constexpr bool
+test02()
+{
+  std::wstring_view 	str_0(L"costa rica");
+  std::wstring_view 	str_1(L"costa marbella");
+  std::wstring_view 	str_2(L"cost");
+  std::wstring_view	str_3(L"costa ricans");
+  std::wstring_view  str_4;
+
+#undef VERIFY
+#define VERIFY(x) if (!(x)) return false
+
+  str_4 = str_0;
+  //comparisons between string_view objects
+  VERIFY( !(str_0 == str_1) );
+  VERIFY( !(str_0 == str_2) );
+  VERIFY( !(str_0 == str_3) );
+  VERIFY( !(str_1 == str_0) );
+  VERIFY( !(str_2 == str_0) );
+  VERIFY( !(str_3 == str_0) );
+  VERIFY( str_4 == str_0 );
+  VERIFY( str_0 == str_4 );
+
+  VERIFY( str_0 != str_1 );
+  VERIFY( str_0 != str_2 );
+  VERIFY( str_0 != str_3 );
+  VERIFY( str_1 != str_0 );
+  VERIFY( str_2 != str_0 );
+  VERIFY( str_3 != str_0 );
+  VERIFY( !(str_0 != str_4) );
+  VERIFY( !(str_4 != str_0) );
+
+  VERIFY( str_0 > str_1 ); //true cuz r>m
+  VERIFY( str_0 > str_2 );
+  VERIFY( !(str_0 > str_3) );
+  VERIFY( !(str_1 > str_0) ); //false cuz m<r
+  VERIFY( !(str_2 > str_0) );
+  VERIFY( str_3 > str_0 );
+  VERIFY( !(str_0 > str_4) );
+  VERIFY( !(str_4 > str_0) );
+
+  VERIFY( !(str_0 < str_1) ); //false cuz r>m
+  VERIFY( !(str_0 < str_2) );
+  VERIFY( str_0 < str_3 );
+  VERIFY( str_1 < str_0 ); //true cuz m<r
+  VERIFY( str_2 < str_0 );
+  VERIFY( !(str_3 < str_0) );
+  VERIFY( !(str_0 < str_4) );
+  VERIFY( !(str_4 < str_0) );
+
+  VERIFY( str_0 >= str_1 ); //true cuz r>m
+  VERIFY( str_0 >= str_2 );
+  VERIFY( !(str_0 >= str_3) );
+  VERIFY( !(str_1 >= str_0) );//false cuz m<r
+  VERIFY( !(str_2 >= str_0) );
+  VERIFY( str_3 >= str_0 );
+  VERIFY( str_0 >= str_4 );
+  VERIFY( str_4 >= str_0 );
+
+  VERIFY( !(str_0 <= str_1) );//false cuz r>m
+  VERIFY( !(str_0 <= str_2) );
+  VERIFY( str_0 <= str_3 );
+  VERIFY( str_1 <= str_0 );//true cuz m<r
+  VERIFY( str_2 <= str_0 );
+  VERIFY( !(str_3 <= str_0) );
+  VERIFY( str_0 <= str_4 );
+  VERIFY( str_4 <= str_0 );
+
+  //comparisons between string_view object and string_view literal
+  VERIFY( !(str_0 == L"costa marbella") );
+  VERIFY( !(str_0 == L"cost") );
+  VERIFY( !(str_0 == L"costa ricans") );
+  VERIFY( !(L"costa marbella" == str_0) );
+  VERIFY( !(L"cost" == str_0) );
+  VERIFY( !(L"costa ricans" == str_0) );
+  VERIFY( L"costa rica" == str_0 );
+  VERIFY( str_0 == L"costa rica" );
+
+  VERIFY( str_0 != L"costa marbella" );
+  VERIFY( str_0 != L"cost" );
+  VERIFY( str_0 != L"costa ricans" );
+  VERIFY( L"costa marbella" != str_0 );
+  VERIFY( L"cost" != str_0 );
+  VERIFY( L"costa ricans" != str_0 );
+  VERIFY( !(L"costa rica" != str_0) );
+  VERIFY( !(str_0 != L"costa rica") );
+
+  VERIFY( str_0 > L"costa marbella" ); //true cuz r>m
+  VERIFY( str_0 > L"cost" );
+  VERIFY( !(str_0 > L"costa ricans") );
+  VERIFY( !(L"costa marbella" > str_0) );//false cuz m<r
+  VERIFY( !(L"cost" > str_0) );
+  VERIFY( L"costa ricans" > str_0 );
+  VERIFY( !(L"costa rica" > str_0) );
+  VERIFY( !(str_0 > L"costa rica") );
+
+  VERIFY( !(str_0 < L"costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 < L"cost") );
+  VERIFY( str_0 < L"costa ricans" );
+  VERIFY( L"costa marbella" < str_0 );//true cuz m<r
+  VERIFY( L"cost" < str_0 );
+  VERIFY( !(L"costa ricans" < str_0) );
+  VERIFY( !(L"costa rica" < str_0) );
+  VERIFY( !(str_0 < L"costa rica") );
+
+  VERIFY( str_0 >= L"costa marbella" );//true cuz r>m
+  VERIFY( str_0 >= L"cost" );
+  VERIFY( !(str_0 >= L"costa ricans") );
+  VERIFY( !(L"costa marbella" >= str_0) );//false cuz m<r
+  VERIFY( !(L"cost" >= str_0) );
+  VERIFY( L"costa ricans" >= str_0 );
+  VERIFY( L"costa rica" >= str_0 );
+  VERIFY( str_0 >= L"costa rica" );
+
+  VERIFY( !(str_0 <= L"costa marbella") );//false cuz r>m
+  VERIFY( !(str_0 <= L"cost") );
+  VERIFY( str_0 <= L"costa ricans" );
+  VERIFY( L"costa marbella" <= str_0 );//true cuz m<r
+  VERIFY( L"cost" <= str_0 );
+  VERIFY( !(L"costa ricans" <= str_0) );
+  VERIFY( L"costa rica" <= str_0 );
+  VERIFY( str_0 <= L"costa rica" );
+
+  return true;
+}
+
+int
+main()
+{
+  test01();
+  static_assert( test02() );
+}
diff --git a/gdb/unittests/basic_string_view/range_access/char/1.cc b/gdb/unittests/basic_string_view/range_access/char/1.cc
new file mode 100644
index 000000000000..162ddeec24e3
--- /dev/null
+++ b/gdb/unittests/basic_string_view/range_access/char/1.cc
@@ -0,0 +1,47 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// C++17 27.7, range access [iterator.range]
+
+#include <string_view>
+
+void
+test01()
+{
+  std::string_view s("Hello, World!");
+  std::begin(s);
+  std::end(s);
+  std::rbegin(s);
+  std::rend(s);
+}
+
+void
+test02()
+{
+  constexpr std::string_view s("Hello, World!");
+  [[maybe_unused]] constexpr auto b = std::begin(s);
+  [[maybe_unused]] constexpr auto e = std::end(s);
+  [[maybe_unused]] constexpr auto cb = std::cbegin(s);
+  [[maybe_unused]] constexpr auto ce = std::cend(s);
+  [[maybe_unused]] constexpr auto rb = std::rbegin(s);
+  [[maybe_unused]] constexpr auto re = std::rend(s);
+  [[maybe_unused]] constexpr auto crb = std::crbegin(s);
+  [[maybe_unused]] constexpr auto cre = std::crend(s);
+}
diff --git a/gdb/unittests/basic_string_view/range_access/wchar_t/1.cc b/gdb/unittests/basic_string_view/range_access/wchar_t/1.cc
new file mode 100644
index 000000000000..6584d253fea8
--- /dev/null
+++ b/gdb/unittests/basic_string_view/range_access/wchar_t/1.cc
@@ -0,0 +1,47 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// C++17 27.7, range access [iterator.range]
+
+#include <string_view>
+
+void
+test01()
+{
+  std::wstring_view ws(L"Hello, World!");
+  std::begin(ws);
+  std::end(ws);
+  std::rbegin(ws);
+  std::rend(ws);
+}
+
+void
+test02()
+{
+  constexpr std::wstring_view ws(L"Hello, World!");
+  [[maybe_unused]] constexpr auto b = std::begin(ws);
+  [[maybe_unused]] constexpr auto e = std::end(ws);
+  [[maybe_unused]] constexpr auto cb = std::cbegin(ws);
+  [[maybe_unused]] constexpr auto ce = std::cend(ws);
+  [[maybe_unused]] constexpr auto rb = std::rbegin(ws);
+  [[maybe_unused]] constexpr auto re = std::rend(ws);
+  [[maybe_unused]] constexpr auto crb = std::crbegin(ws);
+  [[maybe_unused]] constexpr auto cre = std::crend(ws);
+}
diff --git a/gdb/unittests/basic_string_view/requirements/explicit_instantiation/1.cc b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/1.cc
new file mode 100644
index 000000000000..a29d6beb7d2a
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/1.cc
@@ -0,0 +1,26 @@ 
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+
+// This file tests explicit instantiation of basic_string
+
+#include <string_view>
+
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+
+template class std::basic_string_view<int, std::char_traits<int>>;
diff --git a/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc
new file mode 100644
index 000000000000..6f3fca9286d6
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc
@@ -0,0 +1,23 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+template class std::basic_string_view<char>;
diff --git a/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc
new file mode 100644
index 000000000000..46e8e15130d4
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc
@@ -0,0 +1,24 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+// { dg-require-cstdint "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+template class std::basic_string_view<char16_t>;
diff --git a/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc
new file mode 100644
index 000000000000..031fd4c8ecf1
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc
@@ -0,0 +1,24 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+// { dg-require-cstdint "" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+template class std::basic_string_view<char32_t>;
diff --git a/gdb/unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc
new file mode 100644
index 000000000000..8c9ef863a673
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc
@@ -0,0 +1,23 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+template class std::basic_string_view<wchar_t>;
diff --git a/gdb/unittests/basic_string_view/requirements/typedefs.cc b/gdb/unittests/basic_string_view/requirements/typedefs.cc
new file mode 100644
index 000000000000..bdbcfa10ce86
--- /dev/null
+++ b/gdb/unittests/basic_string_view/requirements/typedefs.cc
@@ -0,0 +1,47 @@ 
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+#include <testsuite_containers.h>
+
+namespace __gnu_test
+{
+  template<typename _Tp1, typename _Tp2>
+    struct traits<std::basic_string_view<_Tp1, _Tp2>> : public traits_base
+    {
+      typedef std::true_type    is_container;
+      typedef std::true_type    is_reversible;
+    };
+}
+
+#include <testsuite_containers.h>
+
+// Check container for required typedefs.
+
+__gnu_test::basic_types<std::string_view> t1b;
+__gnu_test::reversible_types<std::string_view> t1r;
+typedef typename std::string_view::traits_type traits_type1;
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+__gnu_test::basic_types<std::wstring_view> t2b;
+__gnu_test::reversible_types<std::wstring_view> t2r;
+typedef typename std::wstring_view::traits_type traits_type2;
+#endif
diff --git a/gdb/unittests/basic_string_view/typedefs.cc b/gdb/unittests/basic_string_view/typedefs.cc
new file mode 100644
index 000000000000..d1269db2b762
--- /dev/null
+++ b/gdb/unittests/basic_string_view/typedefs.cc
@@ -0,0 +1,36 @@ 
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2014-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string_view>
+
+template<typename C, typename T>
+  using check1_t = std::basic_string_view<C, T>;
+
+using check2_t = std::string_view;
+
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+using check3_t = std::u16string_view;
+using check4_t = std::u32string_view;
+#endif
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+using check5_t = std::wstring_view;
+#endif
+
diff --git a/gdb/unittests/basic_string_view/types/1.cc b/gdb/unittests/basic_string_view/types/1.cc
new file mode 100644
index 000000000000..3914053311f4
--- /dev/null
+++ b/gdb/unittests/basic_string_view/types/1.cc
@@ -0,0 +1,43 @@ 
+//
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+//
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+#include <string_view>
+
+struct T
+{
+  typedef std::string_view String_view;
+  typedef String_view::iterator iterator;
+  typedef String_view::const_iterator const_iterator;
+
+  char t(iterator f)             { return *f; }
+  char t(const_iterator f) const { return *f; }
+};
+
+void
+f()
+{
+  std::string_view s;
+  T t;
+  T::const_iterator i = s.begin();
+  
+  t.t(i);
+}