https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89130
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Tue Feb 5 14:45:00 2019 New Revision: 268537 URL: https://gcc.gnu.org/viewcvs?rev=268537&root=gcc&view=rev Log: PR libstdc++/89130 restore support for non-MoveConstructible types The changes to "relocate" std::vector elements can lead to new errors outside the immediate context, because moving the elements to new storage no longer makes use of the move-if-noexcept utilities. This means that types with deleted moves no longer degenerate to copies, but are just ill-formed. The errors happen while instantiating the noexcept-specifier for __relocate_object_a, when deciding whether to try to relocate. This patch introduces indirections to avoid the ill-formed instantiations of std::__relocate_object_a. In order to avoid using if-constexpr prior to C++17 this is done by tag dispatching. After this patch all uses of std::__relocate_a are guarded by checks that will support sensible code (i.e. code not using custom allocators that fool the new checks). PR libstdc++/89130 * include/bits/alloc_traits.h (__is_copy_insertable_impl): Rename to __is_alloc_insertable_impl. Replace single type member with two members, one for each of copy and move insertable. (__is_move_insertable): New trait for internal use. * include/bits/stl_vector.h (vector::_S_nothrow_relocate(true_type)) (vector::_S_nothrow_relocate(true_type)): New functions to conditionally check if __relocate_a can throw. (vector::_S_use_relocate()): Dispatch to _S_nothrow_relocate based on __is_move_insertable. (vector::_S_do_relocate): New overloaded functions to conditionally call __relocate_a. (vector::_S_relocate): New function that dispatches to _S_do_relocate based on _S_use_relocate. * include/bits/vector.tcc (vector::reserve, vector::_M_realloc_insert) (vector::_M_default_append): Call _S_relocate instead of __relocate_a. * testsuite/23_containers/vector/modifiers/push_back/89130.cc: New. Added: trunk/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89130.cc Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/bits/alloc_traits.h trunk/libstdc++-v3/include/bits/stl_vector.h trunk/libstdc++-v3/include/bits/vector.tcc
