[Bug libstdc++/67572] New: std::atomic, std::mutex and others are trivially copyable

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67572

            Bug ID: 67572
           Summary: std::atomic, std::mutex and others are trivially
                    copyable
           Product: gcc
           Version: 4.9.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

#include <atomic>
#include <mutex>
#include <shared_mutex>
#include <type_traits>

static_assert( !std::is_trivially_copyable<std::atomic<int>>::value,
"atomic<int>" );
static_assert( !std::is_trivially_copyable<std::mutex>::value, "mutex" );
static_assert( !std::is_trivially_copyable<std::timed_mutex>::value,
"timed_mutex" );
static_assert( !std::is_trivially_copyable<std::shared_timed_mutex>::value,
"shared_timed_mutex" );

Being non-copyable and non-movable doesn't stop a type being non-trivially
copyable, so to ensure users don't think it's OK to memcpy these types we need
to fix them (e.g. by adding a user-defined destructor).