Deprecate nested types in std::hash

	* include/bits/c++config (_GLIBCXX17_DEPRECATED): Define.
	* include/bits/functional_hash.h (__hash_base::result_type)
	(__hash_base::argument_type): Add _GLIBCXX17_DEPRECATED.
	* include/std/optional (hash<optional<T>>::result_type)
	(hash<optional<T>>::argument_type): Add deprecated attribute.
	(__is_fast_hash<hash<optional<T>>>): Add partial specialization.
	* include/std/variant (hash<variant<Types...>>::result_type)
	(hash<variant<Types...>>::argument_type): Add deprecated attribute.
	(__is_fast_hash<hash<variant<Types...>>>): Add partial specialization.

From-SVN: r253017

libstdc++-v3/ChangeLog

 2017-09-20  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/bits/c++config (_GLIBCXX17_DEPRECATED): Define.
+	* include/bits/functional_hash.h (__hash_base::result_type)
+	(__hash_base::argument_type): Add _GLIBCXX17_DEPRECATED.
+	* include/std/optional (hash<optional<T>>::result_type)
+	(hash<optional<T>>::argument_type): Add deprecated attribute.
+	(__is_fast_hash<hash<optional<T>>>): Add partial specialization.
+	* include/std/variant (hash<variant<Types...>>::result_type)
+	(hash<variant<Types...>>::argument_type): Add deprecated attribute.
+	(__is_fast_hash<hash<variant<Types...>>>): Add partial specialization.
+
 	* libsupc++/exception_ptr.h (copy_exception): Remove deprecated
 	non-standard function.
 

libstdc++-v3/include/bits/c++config

@@ -77,6 +77,7 @@
 // Macros for deprecated attributes.
 //   _GLIBCXX_USE_DEPRECATED
 //   _GLIBCXX_DEPRECATED
+//   _GLIBCXX17_DEPRECATED
 #ifndef _GLIBCXX_USE_DEPRECATED
 # define _GLIBCXX_USE_DEPRECATED 1
 #endif
@@ -87,6 +88,12 @@
 # define _GLIBCXX_DEPRECATED
 #endif
 
+#if defined(__DEPRECATED) && (__cplusplus >= 201703L)
+# define _GLIBCXX17_DEPRECATED [[__deprecated__]]
+#else
+# define _GLIBCXX17_DEPRECATED
+#endif
+
 // Macros for ABI tag attributes.
 #ifndef _GLIBCXX_ABI_TAG_CXX11
 # define _GLIBCXX_ABI_TAG_CXX11 __attribute ((__abi_tag__ ("cxx11")))

libstdc++-v3/include/bits/functional_hash.h

@@ -49,8 +49,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Result, typename _Arg>
     struct __hash_base
     {
-      typedef _Result     result_type;
-      typedef _Arg      argument_type;
+      typedef _Result     result_type _GLIBCXX17_DEPRECATED;
+      typedef _Arg      argument_type _GLIBCXX17_DEPRECATED;
     };
 
   /// Primary class template hash.

libstdc++-v3/include/std/optional

@@ -1028,10 +1028,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : private __poison_hash<remove_const_t<_Tp>>,
       public __optional_hash_call_base<_Tp>
     {
-      using result_type = size_t;
-      using argument_type = optional<_Tp>;
+      using result_type [[__deprecated__]] = size_t;
+      using argument_type [[__deprecated__]] = optional<_Tp>;
     };
 
+  template<typename _Tp>
+    struct __is_fast_hash<hash<optional<_Tp>>> : __is_fast_hash<hash<_Tp>>
+    { };
+
   /// @}
 
   template <typename _Tp> optional(_Tp) -> optional<_Tp>;

libstdc++-v3/include/std/variant

@@ -1420,15 +1420,15 @@ namespace __variant
 	variant<_Types...>, std::index_sequence_for<_Types...>>,
       public __variant_hash_call_base<_Types...>
     {
-      using result_type = size_t;
-      using argument_type = variant<_Types...>;
+      using result_type [[__deprecated__]] = size_t;
+      using argument_type [[__deprecated__]] = variant<_Types...>;
     };
 
   template<>
     struct hash<monostate>
     {
-      using result_type = size_t;
-      using argument_type = monostate;
+      using result_type [[__deprecated__]] = size_t;
+      using argument_type [[__deprecated__]] = monostate;
 
       size_t
       operator()(const monostate& __t) const noexcept
@@ -1438,6 +1438,11 @@ namespace __variant
       }
     };
 
+  template<typename... _Types>
+    struct __is_fast_hash<hash<variant<_Types...>>>
+    : bool_constant<(__is_fast_hash<_Types>::value && ...)>
+    { };
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std