[Bug libstdc++/80316] std::promise treats no shared state as undefined

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80316

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Tue Jul 11 11:52:14 2017
New Revision: 250126

URL: https://gcc.gnu.org/viewcvs?rev=250126&root=gcc&view=rev
Log:
PR libstdc++/80316 make promise::set_value throw no_state error

Backport from mainline
2017-04-21  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/80316
        * include/std/future (_State_baseV2::_Setter::operator()): Remove
        _S_check calls that are done after the pointer to the shared state is
        already dereferenced.
        (_State_baseV2::_Setter<_Res, void>): Define specialization for void
        as partial specialization so it can be defined within the definition
        of _State_baseV2.
        (_State_baseV2::__setter): Call _S_check.
        (_State_baseV2::__setter(promise<void>*)): Add overload for use by
        promise<void>::set_value and promise<void>::set_value_at_thread_exit.
        (promise<T>, promise<T&>, promise<void>): Make _State a friend.
        (_State_baseV2::_Setter<void, void>): Remove explicit specialization.
        (promise<void>::set_value, promise<void>::set_value_at_thread_exit):
        Use new __setter overload.
        * testsuite/30_threads/promise/members/at_thread_exit2.cc: New test.
        * testsuite/30_threads/promise/members/set_exception.cc: Test
        promise<T&> and promise<void> specializations.
        * testsuite/30_threads/promise/members/set_exception2.cc: Likewise.
        Test for no_state error condition.
        * testsuite/30_threads/promise/members/set_value2.cc: Likewise.

Added:
   
branches/gcc-7-branch/libstdc++-v3/testsuite/30_threads/promise/members/at_thread_exit2.cc
Modified:
    branches/gcc-7-branch/libstdc++-v3/ChangeLog
    branches/gcc-7-branch/libstdc++-v3/include/std/future
   
branches/gcc-7-branch/libstdc++-v3/testsuite/30_threads/promise/members/set_exception.cc
   
branches/gcc-7-branch/libstdc++-v3/testsuite/30_threads/promise/members/set_exception2.cc
   
branches/gcc-7-branch/libstdc++-v3/testsuite/30_threads/promise/members/set_value2.cc