https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87044
Bug ID: 87044
Summary: stl_construct.h not interoperable with allocators with
custom reference types
Product: gcc
Version: 8.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: barmie.brace at outlook dot com
Target Milestone: ---
Created attachment 44568
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44568&action=edit
Custom allocator with custom reference object type.
STL containers don't seem to be interoperable with allocators with custom
reference types due to stl_construct.h's use of std::__addressof() instead of
the allocator's address() member.
Attached is a simple example using an allocator with a custom reference type.
[xiii@ea1c9ec7dba3 custom_allocator_test]$ make
g++ test.cpp -o test -std=gnu++14 -O3
In file included from /usr/include/c++/8.2.0/vector:62,
from test.cpp:1:
/usr/include/c++/8.2.0/bits/stl_construct.h: In instantiation of 'void
std::_Destroy(_ForwardIterator, _ForwardIterator, _Allocator&) [with
_ForwardIterator = custom_ptr<int>; _Allocator = custom_allocator<int>]':
/usr/include/c++/8.2.0/bits/stl_vector.h:567:15: required from
'std::vector<_Tp, _Alloc>::~vector() [with _Tp = int; _Alloc =
custom_allocator<int>]'
test.cpp:12:43: required from here
/usr/include/c++/8.2.0/bits/stl_construct.h:198:46: error: cannot bind
non-const lvalue reference of type 'custom_ref<int>&' to an rvalue of type
'custom_ptr<int>::reference' {aka 'custom_ref<int>'}
__traits::destroy(__alloc, std::__addressof(*__first));
^~~~~~~~
In file included from /usr/include/c++/8.2.0/bits/stl_pair.h:59,
from /usr/include/c++/8.2.0/bits/stl_algobase.h:64,
from /usr/include/c++/8.2.0/vector:60,
from test.cpp:1:
/usr/include/c++/8.2.0/bits/move.h:47:5: note: initializing argument 1 of
'constexpr _Tp* std::__addressof(_Tp&) [with _Tp = custom_ref<int>]'
__addressof(_Tp& __r) _GLIBCXX_NOEXCEPT
^~~~~~~~~~~
make: *** [Makefile:2: test] Error 1
