xref: /llvm-project/libcxx/test/std/containers/from_range_helpers.h (revision f1db578f0d0f9d83f8b8b88d92ad5397377a74b2)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef SUPPORT_FROM_RANGE_HELPERS_H
10 #define SUPPORT_FROM_RANGE_HELPERS_H
11 
12 #include <array>
13 #include <cstddef>
14 #include <iterator>
15 #include <type_traits>
16 #include <vector>
17 
18 #include "min_allocator.h"
19 #include "test_allocator.h"
20 #include "test_iterators.h"
21 #include "test_macros.h"
22 #include "type_algorithms.h"
23 
24 struct Empty {};
25 
26 template <class T>
27 struct InputRange {
28   cpp20_input_iterator<T*> begin();
29   sentinel_wrapper<cpp20_input_iterator<T*>> end();
30 };
31 
32 template <class Iter, class Sent, std::ranges::input_range Range>
wrap_input(Range && input)33 constexpr auto wrap_input(Range&& input) {
34   auto b = Iter(std::ranges::begin(input));
35   auto e = Sent(Iter(std::ranges::end(input)));
36   return std::ranges::subrange(std::move(b), std::move(e));
37 }
38 
39 template <class Iter, class Sent, class T, std::size_t N>
wrap_input(std::array<T,N> & input)40 constexpr auto wrap_input(std::array<T, N>& input) {
41   auto b = Iter(input.data());
42   auto e = Sent(Iter(input.data() + input.size()));
43   return std::ranges::subrange(std::move(b), std::move(e));
44 }
45 
46 template <class Iter, class Sent, class T>
wrap_input(std::vector<T> & input)47 constexpr auto wrap_input(std::vector<T>& input) {
48   auto b = Iter(input.data());
49   auto e = Sent(Iter(input.data() + input.size()));
50   return std::ranges::subrange(std::move(b), std::move(e));
51 }
52 
53 struct KeyValue {
54   int key; // Only the key is considered for equality comparison.
55   char value; // Allows distinguishing equivalent instances.
56 
57   bool operator<(const KeyValue& other) const { return key < other.key; }
58   bool operator==(const KeyValue& other) const { return key == other.key; }
59 };
60 
61 template <>
62 struct std::hash<KeyValue> {
63   std::size_t operator()(const KeyValue& kv) const {
64     return kv.key;
65   }
66 };
67 
68 #if !defined(TEST_HAS_NO_EXCEPTIONS)
69 
70 template <class T>
71 struct ThrowingAllocator {
72   using value_type = T;
73   using char_type = T;
74   using is_always_equal = std::false_type;
75 
76   ThrowingAllocator() = default;
77 
78   template <class U>
79   ThrowingAllocator(const ThrowingAllocator<U>&) {}
80 
81   T* allocate(std::size_t) { throw 1; }
82   void deallocate(T*, std::size_t) {}
83 
84   template <class U>
85   friend bool operator==(const ThrowingAllocator&, const ThrowingAllocator<U>&) {
86     return true;
87   }
88 };
89 #endif
90 
91 template <class T, class Func>
92 constexpr void for_all_iterators_and_allocators(Func f) {
93   using Iterators = types::type_list<
94     cpp20_input_iterator<T*>,
95     forward_iterator<T*>,
96     bidirectional_iterator<T*>,
97     random_access_iterator<T*>,
98     contiguous_iterator<T*>,
99     T*
100   >;
101 
102   types::for_each(Iterators{}, [=]<class Iter>() {
103     f.template operator()<Iter, sentinel_wrapper<Iter>, std::allocator<T>>();
104     f.template operator()<Iter, sentinel_wrapper<Iter>, test_allocator<T>>();
105     f.template operator()<Iter, sentinel_wrapper<Iter>, min_allocator<T>>();
106     f.template operator()<Iter, sentinel_wrapper<Iter>, safe_allocator<T>>();
107 
108     if constexpr (std::sentinel_for<Iter, Iter>) {
109       f.template operator()<Iter, Iter, std::allocator<T>>();
110       f.template operator()<Iter, Iter, test_allocator<T>>();
111       f.template operator()<Iter, Iter, min_allocator<T>>();
112       f.template operator()<Iter, Iter, safe_allocator<T>>();
113     }
114   });
115 }
116 
117 #endif // SUPPORT_FROM_RANGE_HELPERS_H
118