Method notify

include/exec/when_any.hpp:101–126

      template <class _Tag, class... _Args>
      void notify(_Tag, _Args&&... __args) noexcept
      {
        using __result_t = __decayed_tuple<_Tag, _Args...>;
        bool __expect    = false;
        if (__emplaced_.compare_exchange_strong(__expect,
                                                true,
                                                __std::memory_order_relaxed,
                                                __std::memory_order_relaxed))
        {
          // This emplacement can happen only once
          if constexpr ((__nothrow_decay_copyable<_Args> && ...))
          {
            __result_.template emplace<__result_t>(_Tag{}, static_cast<_Args&&>(__args)...);
          }
          else
          {
            STDEXEC_TRY
            {
              __result_.template emplace<__result_t>(_Tag{}, static_cast<_Args&&>(__args)...);
            }
            STDEXEC_CATCH_ALL
            {
              using __error_t = __tuple<set_error_t, std::exception_ptr>;
              __result_.template emplace<__error_t>(set_error_t{}, std::current_exception());
            }
          }
          // stop pending operations
          __stop_source_.request_stop();
        }