I had a giant misunderstanding of what 'synchronizes with' meant in [futures.async]/p5. This invalidated the current design of async in <future>. This is a new design, based on my new understanding, which has been confirmed on the lwg mailing list. The summary is that ~future() (and ~shared_future()) will block when they are created from within async, and the thread hasn't finished yet. As part of this work I created two new type traits: __invokable<F, Args...>::value and __invoke_of<F, Args...>::type. These are what result_of<F(Args...)> wanted to be when it grew up, but never will be. __invoke_of is carefully crafted so that it can serve as its own enable_if (type doesn't exist if the signature isn't invokable). All of this work is C++11 only.

llvm-svn: 131639

1 files changed, 1 insertions, 1 deletions

diff --git a/libcxx/include/mutex b/libcxx/include/mutex
index fcfe4b71d89..69192a82f3d 100644
--- a/libcxx/include/mutex
+++ b/libcxx/include/mutex
@@ -485,7 +485,7 @@ private:
     _LIBCPP_INLINE_VISIBILITY
     void __execute(__tuple_indices<_Indices...>)
     {
-        _STD::move(_STD::get<0>(__f_))(_STD::move(_STD::get<_Indices>(__f_))...);
+        __invoke(_STD::move(_STD::get<0>(__f_)), _STD::move(_STD::get<_Indices>(__f_))...);
     }
 };