PR libstdc++/87809 avoid invalid expressions in exception specifications
If the allocator isn't default constructible then checking if the
default constructor throws in an exception specification makes the
declaration invalid. Use the type trait instead.
PR libstdc++/87809
* include/bits/forward_list.h (_Fwd_list_impl::_Fwd_list_impl()): Use
trait in exception-specification instead of possibly invalid
expression.
* include/bits/stl_bvector.h (_Bvector_impl::_Bvector_impl()):
Likewise.
* include/bits/stl_list.h (_List_impl::_List_impl()): Likewise.
* include/bits/stl_vector.h (_Vector_impl::_Vector_impl()): Likewise.
* testsuite/23_containers/forward_list/cons/87809.cc: New test.
* testsuite/23_containers/list/cons/87809.cc: New test.
* testsuite/23_containers/vector/bool/cons/87809.cc: New test.
* testsuite/23_containers/vector/cons/87809.cc: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265626 138bc75d-0d04-0410-961f-82ee72b054a4