[libcxx] Fix PR 22468 - std::function<void()> does not accept non-void-returning functions
Summary:
The bug can be found here: http://llvm.org/bugs/show_bug.cgi?id=22468
`__invoke_void_return_wrapper` is needed to properly handle calling a function that returns a value but where the std::function return type is void. Without this '-Wsystem-headers' will cause `function::operator()(...)` to not compile.
Reviewers: eugenis, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7444
llvm-svn: 228705
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 54519a6be9296fb115b949f1f0785d9cbfacc7c5
diff --git a/include/functional b/include/functional
index d14b46b..36d422c 100644
--- a/include/functional
+++ b/include/functional
@@ -1367,7 +1367,8 @@
_Rp
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
{
- return __invoke(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
+ typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+ return _Invoker::__call(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
}
#ifndef _LIBCPP_NO_RTTI
@@ -1429,7 +1430,7 @@
template <class _Fp>
struct __callable<_Fp, true>
{
- static const bool value =
+ static const bool value = is_same<void, _Rp>::value ||
is_convertible<typename __invoke_of<_Fp&, _ArgTypes...>::type,
_Rp>::value;
};