libstdc++: Check feature test macros in unordered containers

Replace some `__cplusplus > 201402L` preprocessor checks with more
expressive checks for the appropriate feature test macros.

libstdc++-v3/ChangeLog:

	* include/bits/unordered_map.h: Check __glibcxx_node_extract and
	__glibcxx_unordered_map_try_emplace instead of __cplusplus.
	* include/bits/unordered_set.h: Check __glibcxx_node_extract
	instead of __cplusplus.

2 files changed, 26 insertions, 26 deletions

diff --git a/libstdc++-v3/include/bits/unordered_map.h b/libstdc++-v3/include/bits/unordered_map.h
index 8607944..3b47253 100644
--- a/libstdc++-v3/include/bits/unordered_map.h
+++ b/libstdc++-v3/include/bits/unordered_map.h
@@ -137,7 +137,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       typedef typename _Hashtable::difference_type	difference_type;
       ///@}
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       using node_type = typename _Hashtable::node_type;
       using insert_return_type = typename _Hashtable::insert_return_type;
 #endif
@@ -426,7 +426,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	emplace_hint(const_iterator __pos, _Args&&... __args)
 	{ return _M_h.emplace_hint(__pos, std::forward<_Args>(__args)...); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       /// Extract a node.
       node_type
       extract(const_iterator __pos)
@@ -449,7 +449,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       iterator
       insert(const_iterator, node_type&& __nh)
       { return _M_h._M_reinsert_node(std::move(__nh)).position; }
-#endif // C++17
+#endif // node_extract
 
 #ifdef __glibcxx_unordered_map_try_emplace // C++ >= 17 && HOSTED
       /**
@@ -636,7 +636,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       { _M_h.insert(__l); }
 
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_unordered_map_try_emplace // >= C++17 && HOSTED
       /**
        *  @brief Attempts to insert a std::pair into the %unordered_map.
        *  @param __k    Key to use for finding a possibly existing pair in
@@ -728,7 +728,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	    __ret.first->second = std::forward<_Obj>(__obj);
 	  return __ret.first;
 	}
-#endif
+#endif // unordered_map_try_emplace
 
       ///@{
       /**
@@ -813,7 +813,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       noexcept( noexcept(_M_h.swap(__x._M_h)) )
       { _M_h.swap(__x._M_h); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       template<typename, typename, typename>
 	friend class std::_Hash_merge_helper;
 
@@ -842,7 +842,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	void
 	merge(unordered_multimap<_Key, _Tp, _H2, _P2, _Alloc>&& __source)
 	{ merge(__source); }
-#endif // C++17
+#endif // node_extract
 
       // observers.
 
@@ -1283,7 +1283,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       typedef typename _Hashtable::difference_type	difference_type;
       ///@}
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       using node_type = typename _Hashtable::node_type;
 #endif
 
@@ -1648,7 +1648,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       insert(initializer_list<value_type> __l)
       { _M_h.insert(__l); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       /// Extract a node.
       node_type
       extract(const_iterator __pos)
@@ -1671,7 +1671,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       iterator
       insert(const_iterator __hint, node_type&& __nh)
       { return _M_h._M_reinsert_node_multi(__hint, std::move(__nh)); }
-#endif // C++17
+#endif // node_extract
 
       ///@{
       /**
@@ -1756,7 +1756,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       noexcept( noexcept(_M_h.swap(__x._M_h)) )
       { _M_h.swap(__x._M_h); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       template<typename, typename, typename>
 	friend class std::_Hash_merge_helper;
 
@@ -1787,7 +1787,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	void
 	merge(unordered_map<_Key, _Tp, _H2, _P2, _Alloc>&& __source)
 	{ merge(__source); }
-#endif // C++17
+#endif // node_extract
 
       // observers.
 
@@ -2169,7 +2169,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
 _GLIBCXX_END_NAMESPACE_CONTAINER
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
   // Allow std::unordered_map access to internals of compatible maps.
   template<typename _Key, typename _Val, typename _Hash1, typename _Eq1,
 	   typename _Alloc, typename _Hash2, typename _Eq2>
@@ -2217,7 +2217,7 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
       _S_get_table(unordered_multimap<_Key, _Val, _Hash2, _Eq2, _Alloc>& __map)
       { return __map._M_h; }
     };
-#endif // C++17
+#endif // node_extract
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
diff --git a/libstdc++-v3/include/bits/unordered_set.h b/libstdc++-v3/include/bits/unordered_set.h
index a2fa2b4..08dcfa2 100644
--- a/libstdc++-v3/include/bits/unordered_set.h
+++ b/libstdc++-v3/include/bits/unordered_set.h
@@ -131,7 +131,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       typedef typename _Hashtable::difference_type	difference_type;
       ///@}
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       using node_type = typename _Hashtable::node_type;
       using insert_return_type = typename _Hashtable::insert_return_type;
 #endif
@@ -487,7 +487,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       insert(initializer_list<value_type> __l)
       { _M_h.insert(__l); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       /// Extract a node.
       node_type
       extract(const_iterator __pos)
@@ -510,7 +510,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       iterator
       insert(const_iterator, node_type&& __nh)
       { return _M_h._M_reinsert_node(std::move(__nh)).position; }
-#endif // C++17
+#endif // node_extract
 
       ///@{
       /**
@@ -594,7 +594,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       noexcept( noexcept(_M_h.swap(__x._M_h)) )
       { _M_h.swap(__x._M_h); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       template<typename, typename, typename>
 	friend class std::_Hash_merge_helper;
 
@@ -623,7 +623,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	void
 	merge(unordered_multiset<_Value, _H2, _P2, _Alloc>&& __source)
 	{ merge(__source); }
-#endif // C++17
+#endif // node_extract
 
       // observers.
 
@@ -999,7 +999,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       typedef typename _Hashtable::difference_type	difference_type;
       ///@}
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       using node_type = typename _Hashtable::node_type;
 #endif
 
@@ -1332,7 +1332,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       insert(initializer_list<value_type> __l)
       { _M_h.insert(__l); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       /// Extract a node.
       node_type
       extract(const_iterator __pos)
@@ -1355,7 +1355,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       iterator
       insert(const_iterator __hint, node_type&& __nh)
       { return _M_h._M_reinsert_node_multi(__hint, std::move(__nh)); }
-#endif // C++17
+#endif // node_extract
 
       ///@{
       /**
@@ -1444,7 +1444,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       noexcept( noexcept(_M_h.swap(__x._M_h)) )
       { _M_h.swap(__x._M_h); }
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
       template<typename, typename, typename>
 	friend class std::_Hash_merge_helper;
 
@@ -1475,7 +1475,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	void
 	merge(unordered_set<_Value, _H2, _P2, _Alloc>&& __source)
 	{ merge(__source); }
-#endif // C++17
+#endif // node_extract
 
       // observers.
 
@@ -1838,7 +1838,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
 _GLIBCXX_END_NAMESPACE_CONTAINER
 
-#if __cplusplus > 201402L
+#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
   // Allow std::unordered_set access to internals of compatible sets.
   template<typename _Val, typename _Hash1, typename _Eq1, typename _Alloc,
 	   typename _Hash2, typename _Eq2>
@@ -1885,7 +1885,7 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
       _S_get_table(unordered_multiset<_Val, _Hash2, _Eq2, _Alloc>& __set)
       { return __set._M_h; }
     };
-#endif // C++17
+#endif // node_extract
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std