[libc++] Implement P0433: deduction guides for <unordered_map>

Thanks to Arthur O'Dwyer for the patch.

Differential Revision: https://reviews.llvm.org/D58590

llvm-svn: 366124

1 files changed, 140 insertions, 6 deletions

diff --git a/libcxx/include/unordered_map b/libcxx/include/unordered_map
index 4dfe69868e5..63aecc8bc0e 100644
--- a/libcxx/include/unordered_map
+++ b/libcxx/include/unordered_map
@@ -844,9 +844,9 @@ public:
     // types
     typedef _Key                                           key_type;
     typedef _Tp                                            mapped_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
+    typedef typename __identity<_Hash>::type               hasher;
+    typedef typename __identity<_Pred>::type               key_equal;
+    typedef typename __identity<_Alloc>::type              allocator_type;
     typedef pair<const key_type, mapped_type>              value_type;
     typedef value_type&                                    reference;
     typedef const value_type&                              const_reference;
@@ -1348,6 +1348,73 @@ private:
 #endif
 };
 
+#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
+template<class _InputIterator,
+         class _Hash = hash<__iter_key_type<_InputIterator>>,
+         class _Pred = equal_to<__iter_key_type<_InputIterator>>,
+         class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<!__is_allocator<_Pred>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type = 0,
+              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
+  -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>, _Hash, _Pred, _Allocator>;
+
+template<class _Key, class _Tp, class _Hash = hash<remove_const_t<_Key>>,
+         class _Pred = equal_to<remove_const_t<_Key>>,
+         class _Allocator = allocator<pair<const _Key, _Tp>>,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<!__is_allocator<_Pred>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type = 0,
+              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
+  -> unordered_map<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
+
+template<class _InputIterator, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
+  -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                   hash<__iter_key_type<_InputIterator>>, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _InputIterator, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(_InputIterator, _InputIterator, _Allocator)
+  -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                   hash<__iter_key_type<_InputIterator>>, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _InputIterator, class _Hash, class _Allocator,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
+  -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                   _Hash, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
+  -> unordered_map<remove_const_t<_Key>, _Tp,
+                   hash<remove_const_t<_Key>>,
+                   equal_to<remove_const_t<_Key>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(initializer_list<pair<_Key, _Tp>>, _Allocator)
+  -> unordered_map<remove_const_t<_Key>, _Tp,
+                   hash<remove_const_t<_Key>>,
+                   equal_to<remove_const_t<_Key>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Hash, class _Allocator,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
+  -> unordered_map<remove_const_t<_Key>, _Tp, _Hash,
+                   equal_to<remove_const_t<_Key>>, _Allocator>;
+#endif
+
 template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
 unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
         size_type __n, const hasher& __hf, const key_equal& __eql)
@@ -1673,9 +1740,9 @@ public:
     // types
     typedef _Key                                           key_type;
     typedef _Tp                                            mapped_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
+    typedef typename __identity<_Hash>::type               hasher;
+    typedef typename __identity<_Pred>::type               key_equal;
+    typedef typename __identity<_Alloc>::type              allocator_type;
     typedef pair<const key_type, mapped_type>              value_type;
     typedef value_type&                                    reference;
     typedef const value_type&                              const_reference;
@@ -2041,6 +2108,73 @@ public:
 
 };
 
+#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
+template<class _InputIterator,
+         class _Hash = hash<__iter_key_type<_InputIterator>>,
+         class _Pred = equal_to<__iter_key_type<_InputIterator>>,
+         class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<!__is_allocator<_Pred>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type = 0,
+                   _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
+  -> unordered_multimap<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>, _Hash, _Pred, _Allocator>;
+
+template<class _Key, class _Tp, class _Hash = hash<remove_const_t<_Key>>,
+         class _Pred = equal_to<remove_const_t<_Key>>,
+         class _Allocator = allocator<pair<const _Key, _Tp>>,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<!__is_allocator<_Pred>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type = 0,
+                   _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
+  -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
+
+template<class _InputIterator, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
+  -> unordered_multimap<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                        hash<__iter_key_type<_InputIterator>>, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _InputIterator, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(_InputIterator, _InputIterator, _Allocator)
+  -> unordered_multimap<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                        hash<__iter_key_type<_InputIterator>>, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _InputIterator, class _Hash, class _Allocator,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
+  -> unordered_multimap<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>,
+                        _Hash, equal_to<__iter_key_type<_InputIterator>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
+  -> unordered_multimap<remove_const_t<_Key>, _Tp,
+                        hash<remove_const_t<_Key>>,
+                        equal_to<remove_const_t<_Key>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Allocator,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
+  -> unordered_multimap<remove_const_t<_Key>, _Tp,
+                        hash<remove_const_t<_Key>>,
+                        equal_to<remove_const_t<_Key>>, _Allocator>;
+
+template<class _Key, class _Tp, class _Hash, class _Allocator,
+         class = _EnableIf<!__is_allocator<_Hash>::value>,
+         class = _EnableIf<!is_integral<_Hash>::value>,
+         class = _EnableIf<__is_allocator<_Allocator>::value>>
+unordered_multimap(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
+  -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash,
+                        equal_to<remove_const_t<_Key>>, _Allocator>;
+#endif
+
 template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
 unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
         size_type __n, const hasher& __hf, const key_equal& __eql)