Use requires-clauses and concepts for container-like components sin…

…ce C++20 (#4718)

Co-authored-by: Stephan T. Lavavej <stl@nuwen.net>

stl/inc/deque

@@ -1777,8 +1777,7 @@ deque(_Iter, _Iter, _Alloc = _Alloc()) -> deque<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
 #if _HAS_CXX23
-template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
 deque(from_range_t, _Rng&&, _Alloc = _Alloc()) -> deque<_RANGES range_value_t<_Rng>, _Alloc>;
 #endif // _HAS_CXX23
 

stl/inc/forward_list

@@ -1561,8 +1561,7 @@ forward_list(_Iter, _Iter, _Alloc = _Alloc()) -> forward_list<_Iter_value_t<_Ite
 #endif // _HAS_CXX17
 
 #if _HAS_CXX23
-template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
 forward_list(from_range_t, _Rng&&, _Alloc = _Alloc()) -> forward_list<_RANGES range_value_t<_Rng>, _Alloc>;
 #endif // _HAS_CXX23
 

stl/inc/hash_map

@@ -58,6 +58,11 @@ namespace stdext {
         using _Deduce_key = const _Kty&;
         using key_equal   = _Tr;
 
+#if _HAS_CXX20 && defined(__EDG__) // TRANSITION, DevCom-10678753
+        template <class, class>
+        static constexpr bool _Supports_transparency = false;
+#endif // ^^^ workaround ^^^
+
         _Hmap_traits() = default;
 
         _Hmap_traits(const _Tr& _Traits) noexcept(_STD is_nothrow_copy_constructible_v<_Tr>) : _Tr(_Traits) {}

stl/inc/hash_set

@@ -53,6 +53,11 @@ namespace stdext {
         using _Deduce_key = const _Kty&;
         using key_equal   = _Tr;
 
+#if _HAS_CXX20 && defined(__EDG__) // TRANSITION, DevCom-10678753
+        template <class, class>
+        static constexpr bool _Supports_transparency = false;
+#endif // ^^^ workaround ^^^
+
         _Hset_traits() = default;
 
         _Hset_traits(const _Tr& _Traits) noexcept(_STD is_nothrow_copy_constructible_v<_Tr>) : _Tr(_Traits) {}

stl/inc/list

@@ -1864,8 +1864,7 @@ list(_Iter, _Iter, _Alloc = _Alloc()) -> list<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
 #if _HAS_CXX23
-template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
 list(from_range_t, _Rng&&, _Alloc = _Alloc()) -> list<_RANGES range_value_t<_Rng>, _Alloc>;
 #endif // _HAS_CXX23
 

stl/inc/map

@@ -385,12 +385,12 @@ map(initializer_list<pair<_Kty, _Ty>>, _Alloc) -> map<_Kty, _Ty, less<_Kty>, _Al
 
 #if _HAS_CXX23
 template <_RANGES input_range _Rng, class _Pr = less<_Range_key_type<_Rng>>,
-    class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
-    enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
+    _Allocator_for_container _Alloc = allocator<_Range_to_alloc_type<_Rng>>>
+    requires (!_Allocator_for_container<_Pr>)
 map(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc())
     -> map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Pr, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 map(from_range_t, _Rng&&, _Alloc)
     -> map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, less<_Range_key_type<_Rng>>, _Alloc>;
 #endif // _HAS_CXX23
@@ -616,12 +616,12 @@ multimap(initializer_list<pair<_Kty, _Ty>>, _Alloc) -> multimap<_Kty, _Ty, less<
 
 #if _HAS_CXX23
 template <_RANGES input_range _Rng, class _Pr = less<_Range_key_type<_Rng>>,
-    class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
-    enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
+    _Allocator_for_container _Alloc = allocator<_Range_to_alloc_type<_Rng>>>
+    requires (!_Allocator_for_container<_Pr>)
 multimap(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc())
     -> multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Pr, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 multimap(from_range_t, _Rng&&, _Alloc)
     -> multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, less<_Range_key_type<_Rng>>, _Alloc>;
 #endif // _HAS_CXX23

stl/inc/queue

@@ -50,7 +50,7 @@ public:
         : c(_STD move(_Cont)) {}
 
 #if _HAS_CXX23
-    template <class _InIt, enable_if_t<_Is_iterator_v<_InIt>, int> = 0>
+    template <_Iterator_for_container _InIt>
     queue(_InIt _First, _InIt _Last) noexcept(is_nothrow_constructible_v<_Container, _InIt, _InIt>) // strengthened
         : c(_STD move(_First), _STD move(_Last)) {}
 
@@ -79,8 +79,8 @@ public:
         : c(_STD move(_Right.c), _Al) {}
 
 #if _HAS_CXX23
-    template <class _InIt, class _Alloc,
-        enable_if_t<conjunction_v<_Is_iterator<_InIt>, uses_allocator<_Container, _Alloc>>, int> = 0>
+    template <_Iterator_for_container _InIt, class _Alloc>
+        requires uses_allocator_v<_Container, _Alloc>
     queue(_InIt _First, _InIt _Last, const _Alloc& _Al) noexcept(
         is_nothrow_constructible_v<_Container, _InIt, _InIt, const _Alloc&>) // strengthened
         : c(_STD move(_First), _STD move(_Last), _Al) {}
@@ -169,12 +169,10 @@ queue(_Container, _Alloc) -> queue<typename _Container::value_type, _Container>;
 #endif // _HAS_CXX17
 
 #if _HAS_CXX23
-template <class _InIt, class _Alloc = allocator<_Iter_value_t<_InIt>>,
-    enable_if_t<conjunction_v<_Is_iterator<_InIt>, _Is_allocator<_Alloc>>, int> = 0>
+template <_Iterator_for_container _InIt, _Allocator_for_container _Alloc = allocator<_Iter_value_t<_InIt>>>
 queue(_InIt, _InIt, _Alloc = _Alloc()) -> queue<_Iter_value_t<_InIt>, deque<_Iter_value_t<_InIt>, _Alloc>>;
 
-template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
 queue(from_range_t, _Rng&&, _Alloc = _Alloc())
     -> queue<_RANGES range_value_t<_Rng>, deque<_RANGES range_value_t<_Rng>, _Alloc>>;
 #endif // _HAS_CXX23
@@ -345,15 +343,15 @@ public:
     }
 
 #if _HAS_CXX23
-    template <_Container_compatible_range<_Ty> _Rng, class _Alloc,
-        enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
+    template <_Container_compatible_range<_Ty> _Rng, class _Alloc>
+        requires uses_allocator_v<_Container, _Alloc>
     priority_queue(from_range_t, _Rng&& _Range, const _Pr& _Pred, const _Alloc& _Al)
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range), _Al)), comp(_Pred) {
         _Make_heap();
     }
 
-    template <_Container_compatible_range<_Ty> _Rng, class _Alloc,
-        enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
+    template <_Container_compatible_range<_Ty> _Rng, class _Alloc>
+        requires uses_allocator_v<_Container, _Alloc>
     priority_queue(from_range_t, _Rng&& _Range, const _Alloc& _Al)
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range), _Al)), comp() {
         _Make_heap();

stl/inc/set

@@ -196,11 +196,11 @@ set(initializer_list<_Kty>, _Alloc) -> set<_Kty, less<_Kty>, _Alloc>;
 
 #if _HAS_CXX23
 template <_RANGES input_range _Rng, class _Pr = less<_RANGES range_value_t<_Rng>>,
-    class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
+    _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
+    requires (!_Allocator_for_container<_Pr>)
 set(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc()) -> set<_RANGES range_value_t<_Rng>, _Pr, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 set(from_range_t, _Rng&&, _Alloc) -> set<_RANGES range_value_t<_Rng>, less<_RANGES range_value_t<_Rng>>, _Alloc>;
 #endif // _HAS_CXX23
 #endif // _HAS_CXX17
@@ -410,11 +410,11 @@ multiset(initializer_list<_Kty>, _Alloc) -> multiset<_Kty, less<_Kty>, _Alloc>;
 
 #if _HAS_CXX23
 template <_RANGES input_range _Rng, class _Pr = less<_RANGES range_value_t<_Rng>>,
-    class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
-    enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
+    _Allocator_for_container _Alloc = allocator<_RANGES range_value_t<_Rng>>>
+    requires (!_Allocator_for_container<_Pr>)
 multiset(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc()) -> multiset<_RANGES range_value_t<_Rng>, _Pr, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 multiset(from_range_t, _Rng&&, _Alloc)
     -> multiset<_RANGES range_value_t<_Rng>, less<_RANGES range_value_t<_Rng>>, _Alloc>;
 #endif // _HAS_CXX23

stl/inc/sstream

@@ -230,8 +230,7 @@ public:
     }
 
 #if _HAS_CXX20
-    template <class _Alloc2>
-        requires _Is_allocator<_Alloc2>::value
+    template <_Allocator_for_container _Alloc2>
     _NODISCARD basic_string<_Elem, _Traits, _Alloc2> str(const _Alloc2& _Al) const {
         return basic_string<_Elem, _Traits, _Alloc2>{view(), _Al};
     }
@@ -694,8 +693,7 @@ public:
     }
 
 #if _HAS_CXX20
-    template <class _Alloc2>
-        requires _Is_allocator<_Alloc2>::value
+    template <_Allocator_for_container _Alloc2>
     _NODISCARD basic_string<_Elem, _Traits, _Alloc2> str(const _Alloc2& _Al) const {
         return _Stringbuffer.str(_Al);
     }
@@ -814,7 +812,7 @@ public:
     }
 
 #if _HAS_CXX20
-    template <class _Alloc2, enable_if_t<_Is_allocator<_Alloc2>::value, int> = 0>
+    template <_Allocator_for_container _Alloc2>
     _NODISCARD basic_string<_Elem, _Traits, _Alloc2> str(const _Alloc2& _Al) const {
         return _Stringbuffer.str(_Al);
     }
@@ -939,7 +937,7 @@ public:
     }
 
 #if _HAS_CXX20
-    template <class _Alloc2, enable_if_t<_Is_allocator<_Alloc2>::value, int> = 0>
+    template <_Allocator_for_container _Alloc2>
     _NODISCARD basic_string<_Elem, _Traits, _Alloc2> str(const _Alloc2& _Al) const {
         return _Stringbuffer.str(_Al);
     }

stl/inc/stack

@@ -43,7 +43,7 @@ public:
         : c(_STD move(_Cont)) {}
 
 #if _HAS_CXX23
-    template <class _InIt, enable_if_t<_Is_iterator_v<_InIt>, int> = 0>
+    template <_Iterator_for_container _InIt>
     stack(_InIt _First, _InIt _Last) noexcept(is_nothrow_constructible_v<_Container, _InIt, _InIt>) // strengthened
         : c(_STD move(_First), _STD move(_Last)) {}
 
@@ -72,8 +72,8 @@ public:
         : c(_STD move(_Right.c), _Al) {}
 
 #if _HAS_CXX23
-    template <class _InIt, class _Alloc,
-        enable_if_t<conjunction_v<_Is_iterator<_InIt>, uses_allocator<_Container, _Alloc>>, int> = 0>
+    template <_Iterator_for_container _InIt, class _Alloc>
+        requires uses_allocator_v<_Container, _Alloc>
     stack(_InIt _First, _InIt _Last, const _Alloc& _Al) noexcept(
         is_nothrow_constructible_v<_Container, _InIt, _InIt, const _Alloc&>) // strengthened
         : c(_STD move(_First), _STD move(_Last), _Al) {}
@@ -154,14 +154,13 @@ stack(_Container, _Alloc) -> stack<typename _Container::value_type, _Container>;
 #endif // _HAS_CXX17
 
 #if _HAS_CXX23
-template <class _InIt, class _Alloc = allocator<_Iter_value_t<_InIt>>,
-    enable_if_t<conjunction_v<_Is_iterator<_InIt>, _Is_allocator<_Alloc>>, int> = 0>
+template <_Iterator_for_container _InIt, _Allocator_for_container _Alloc = allocator<_Iter_value_t<_InIt>>>
 stack(_InIt, _InIt, _Alloc = _Alloc()) -> stack<_Iter_value_t<_InIt>, deque<_Iter_value_t<_InIt>, _Alloc>>;
 
 template <_RANGES input_range _Rng>
 stack(from_range_t, _Rng&&) -> stack<_RANGES range_value_t<_Rng>>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 stack(from_range_t, _Rng&&, _Alloc) -> stack<_RANGES range_value_t<_Rng>, deque<_RANGES range_value_t<_Rng>, _Alloc>>;
 #endif // _HAS_CXX23
 

stl/inc/unordered_map

@@ -497,22 +497,22 @@ unordered_map(initializer_list<pair<_Kty, _Ty>>, _Guide_size_type_t<_Alloc>, _Ha
     -> unordered_map<_Kty, _Ty, _Hasher, equal_to<_Kty>, _Alloc>;
 
 #if _HAS_CXX23
-template <_RANGES input_range _Rng, class _Hasher = hash<_Range_key_type<_Rng>>,
-    class _Keyeq = equal_to<_Range_key_type<_Rng>>, class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
-    enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
+template <_RANGES input_range _Rng, _Hasher_for_container _Hasher = hash<_Range_key_type<_Rng>>,
+    class _Keyeq                    = equal_to<_Range_key_type<_Rng>>,
+    _Allocator_for_container _Alloc = allocator<_Range_to_alloc_type<_Rng>>>
+    requires (!_Allocator_for_container<_Keyeq>)
 unordered_map(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc> = 0, _Hasher = _Hasher(), _Keyeq = _Keyeq(),
     _Alloc = _Alloc()) -> unordered_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, _Keyeq, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 unordered_map(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Alloc) -> unordered_map<_Range_key_type<_Rng>,
     _Range_mapped_type<_Rng>, hash<_Range_key_type<_Rng>>, equal_to<_Range_key_type<_Rng>>, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 unordered_map(from_range_t, _Rng&&, _Alloc) -> unordered_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
     hash<_Range_key_type<_Rng>>, equal_to<_Range_key_type<_Rng>>, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
-    enable_if_t<conjunction_v<_Is_hasher<_Hasher>, _Is_allocator<_Alloc>>, int> = 0>
+template <_RANGES input_range _Rng, _Hasher_for_container _Hasher, _Allocator_for_container _Alloc>
 unordered_map(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, equal_to<_Range_key_type<_Rng>>, _Alloc>;
 #endif // _HAS_CXX23
@@ -867,23 +867,23 @@ unordered_multimap(initializer_list<pair<_Kty, _Ty>>, _Guide_size_type_t<_Alloc>
     -> unordered_multimap<_Kty, _Ty, _Hasher, equal_to<_Kty>, _Alloc>;
 
 #if _HAS_CXX23
-template <_RANGES input_range _Rng, class _Hasher = hash<_Range_key_type<_Rng>>,
-    class _Keyeq = equal_to<_Range_key_type<_Rng>>, class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
-    enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
+template <_RANGES input_range _Rng, _Hasher_for_container _Hasher = hash<_Range_key_type<_Rng>>,
+    class _Keyeq                    = equal_to<_Range_key_type<_Rng>>,
+    _Allocator_for_container _Alloc = allocator<_Range_to_alloc_type<_Rng>>>
+    requires (!_Allocator_for_container<_Keyeq>)
 unordered_multimap(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc> = 0, _Hasher = _Hasher(), _Keyeq = _Keyeq(),
     _Alloc = _Alloc()) -> unordered_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, _Keyeq, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 unordered_multimap(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Alloc)
     -> unordered_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, hash<_Range_key_type<_Rng>>,
         equal_to<_Range_key_type<_Rng>>, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
+template <_RANGES input_range _Rng, _Allocator_for_container _Alloc>
 unordered_multimap(from_range_t, _Rng&&, _Alloc) -> unordered_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
     hash<_Range_key_type<_Rng>>, equal_to<_Range_key_type<_Rng>>, _Alloc>;
 
-template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
-    enable_if_t<conjunction_v<_Is_hasher<_Hasher>, _Is_allocator<_Alloc>>, int> = 0>
+template <_RANGES input_range _Rng, _Hasher_for_container _Hasher, _Allocator_for_container _Alloc>
 unordered_multimap(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, equal_to<_Range_key_type<_Rng>>,
         _Alloc>;