Don't neglect to "return *this". git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@165860 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/future b/include/future index 758296a..39475bd 100644 --- a/include/future +++ b/include/future 
@@ -1872,6 +1872,7 @@  __f_ = __f.__f_;  __f.__f_ = nullptr;  } + return *this;  }    template<class _Rp, class ..._ArgTypes>