[10/12] gdbsupport: make basic_safe_iterator::operator* return the same thing as underlying iterator
Commit Message
Using the following patch that removes the reference_to_pointer_iterator
from breakpoint_range, I would get:
CXX breakpoint.o
/home/smarchi/src/binutils-gdb/gdb/breakpoint.c: In function ‘void breakpoint_program_space_exit(program_space*)’:
/home/smarchi/src/binutils-gdb/gdb/breakpoint.c:3030:46: error: cannot allocate an object of abstract type ‘breakpoint’
3030 | for (breakpoint &b : all_breakpoints_safe ())
| ^
In file included from /home/smarchi/src/binutils-gdb/gdb/gdbthread.h:26,
from /home/smarchi/src/binutils-gdb/gdb/infrun.h:21,
from /home/smarchi/src/binutils-gdb/gdb/gdbarch.h:28,
from /home/smarchi/src/binutils-gdb/gdb/arch-utils.h:23,
from /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:21:
/home/smarchi/src/binutils-gdb/gdb/breakpoint.h:619:8: note: because the following virtual functions are pure within ‘breakpoint’:
619 | struct breakpoint : public intrusive_list_node<breakpoint>
| ^~~~~~~~~~
/home/smarchi/src/binutils-gdb/gdb/breakpoint.c:250:1: note: ‘virtual breakpoint::~breakpoint()’
250 | breakpoint::~breakpoint ()
| ^~~~~~~~~~
This is because the operator* method of the basic_safe_iterator iterator
wrapper returns a value_type. So, even if the method of the underlying
iterator (breakpoint_iterator, an intrusive_list iterator) returns a
`breakpoint &`, the method of the wrapper returns a `breakpoint`.
I think it would make sense for iterator wrappers such as
basic_safe_iterator to return the exact same thing as the iterator they
wrap. At least, it fixes my problem.
Change-Id: Ibbcd390ac03d2fb6ae4854923750c8d7c3c04e8a
---
gdbsupport/safe-iterator.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
@@ -19,6 +19,8 @@
#ifndef COMMON_SAFE_ITERATOR_H
#define COMMON_SAFE_ITERATOR_H
+#include "gdbsupport/invoke-result.h"
+
/* A forward iterator that wraps Iterator, such that when iterating
with iterator IT, it is possible to delete *IT without invalidating
IT. Suitably wrapped in a range type and used with range-for, this
@@ -75,7 +77,9 @@ class basic_safe_iterator
basic_safe_iterator ()
{}
- value_type operator* () const { return *m_it; }
+ typename gdb::invoke_result<decltype(&Iterator::operator*), Iterator>::type
+ operator* () const
+ { return *m_it; }
self_type &operator++ ()
{