commit 5f2d5b95e689a041005d9e4eac41ab6c25e94738
author Marshall Clow <mclow.lists@gmail.com> Sat Oct 12 22:49:17 2013 +0000
committer Marshall Clow <mclow.lists@gmail.com> Sat Oct 12 22:49:17 2013 +0000
tree a2b7325a15d28df357cb1ae8f78eb8975605036d
parent 206ce1faaf35284f829bbfcdd28421098509e17e

LWG Issue 2097: packaged_task constructors should be constrained

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192544 91177308-0d34-0410-b5e6-96231b3b80d8

include/future

diff --git a/include/future b/include/future
index 334eaeb..2d969df 100644
--- a/include/future
+++ b/include/future
@@ -2013,10 +2013,26 @@
     // construction and destruction
     _LIBCPP_INLINE_VISIBILITY
     packaged_task() _NOEXCEPT : __p_(nullptr) {}
-    template <class _Fp>
+    template <class _Fp,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+             >
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator>
+    template <class _Fp, class _Allocator,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
              : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
@@ -2128,10 +2144,26 @@
     // construction and destruction
     _LIBCPP_INLINE_VISIBILITY
     packaged_task() _NOEXCEPT : __p_(nullptr) {}
-    template <class _Fp>
+    template <class _Fp,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator>
+    template <class _Fp, class _Allocator,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >    
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
              : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),