Zhihao Yuan: Replace operator& with addressof in reference_wrapper constructor.

llvm-svn: 187927

1 files changed, 52 insertions, 1 deletions

diff --git a/libcxx/include/__functional_base b/libcxx/include/__functional_base
index 2bc2d2c1466..800b4b929c7 100644
--- a/libcxx/include/__functional_base
+++ b/libcxx/include/__functional_base
@@ -365,6 +365,56 @@ struct __invoke_return
     typedef decltype(__invoke(_VSTD::declval<_Tp>(), _VSTD::declval<_Args>()...)) type;
 };
 
+// addressof
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+addressof(_Tp& __x) _NOEXCEPT
+{
+    return (_Tp*)&reinterpret_cast<const volatile char&>(__x);
+}
+
+#if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
+// Objective-C++ Automatic Reference Counting uses qualified pointers
+// that require special addressof() signatures. When
+// _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler
+// itself is providing these definitions. Otherwise, we provide them.
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__strong _Tp*
+addressof(__strong _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+
+#ifdef _LIBCPP_HAS_OBJC_ARC_WEAK
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__weak _Tp*
+addressof(__weak _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+#endif
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__autoreleasing _Tp*
+addressof(__autoreleasing _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__unsafe_unretained _Tp*
+addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+#endif
+
 template <class _Tp>
 class _LIBCPP_TYPE_VIS reference_wrapper
     : public __weak_result_type<_Tp>
@@ -377,7 +427,8 @@ private:
 
 public:
     // construct/copy/destroy
-    _LIBCPP_INLINE_VISIBILITY reference_wrapper(type& __f) _NOEXCEPT : __f_(&__f) {}
+    _LIBCPP_INLINE_VISIBILITY reference_wrapper(type& __f) _NOEXCEPT
+        : __f_(_VSTD::addressof(__f)) {}
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
     private: reference_wrapper(type&&); public: // = delete; // do not bind to temps
 #endif