xref: /llvm-project/libcxx/test/std/algorithms/alg.nonmodifying/alg.find/find.pass.cpp (revision c9535d7b61a37d6fa58e51222a9ccecc54431193)
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 // ADDITIONAL_COMPILE_FLAGS(gcc): -Wno-bool-compare
10 // ADDITIONAL_COMPILE_FLAGS(gcc-style-warnings): -Wno-sign-compare
11 // MSVC warning C4245: conversion from 'int' to 'wchar_t', signed/unsigned mismatch
12 // MSVC warning C4305: truncation from 'int' to 'bool'
13 // MSVC warning C4310: cast truncates constant value
14 // MSVC warning C4389: '==': signed/unsigned mismatch
15 // MSVC warning C4805: '==': unsafe mix of type 'char' and type 'bool' in operation
16 // ADDITIONAL_COMPILE_FLAGS(cl-style-warnings): /wd4245 /wd4305 /wd4310 /wd4389 /wd4805
17 
18 // <algorithm>
19 
20 // template<InputIterator Iter, class T>
21 //   requires HasEqualTo<Iter::value_type, T>
22 //   constexpr Iter   // constexpr after C++17
23 //   find(Iter first, Iter last, const T& value);
24 
25 #include <algorithm>
26 #include <cassert>
27 #include <deque>
28 #include <vector>
29 #include <type_traits>
30 
31 #include "test_macros.h"
32 #include "test_iterators.h"
33 #include "type_algorithms.h"
34 
35 static std::vector<int> comparable_data;
36 
37 template <class ArrayT, class CompareT>
38 struct Test {
39   template <class Iter>
operator ()Test40   TEST_CONSTEXPR_CXX20 void operator()() {
41     ArrayT arr[] = {
42         ArrayT(1), ArrayT(2), ArrayT(3), ArrayT(4), ArrayT(5), ArrayT(6), ArrayT(7), ArrayT(8), ArrayT(9), ArrayT(10)};
43 
44     static_assert(std::is_same<decltype(std::find(Iter(arr), Iter(arr), 0)), Iter>::value, "");
45 
46     { // first element matches
47       Iter iter = std::find(Iter(arr), Iter(arr + 10), CompareT(1));
48       assert(*iter == ArrayT(1));
49       assert(base(iter) == arr);
50     }
51 
52     { // range is empty; return last
53       Iter iter = std::find(Iter(arr), Iter(arr), CompareT(1));
54       assert(base(iter) == arr);
55     }
56 
57     { // if multiple elements match, return the first match
58       ArrayT data[] = {
59           ArrayT(1), ArrayT(2), ArrayT(3), ArrayT(4), ArrayT(5), ArrayT(6), ArrayT(7), ArrayT(5), ArrayT(4)};
60       Iter iter = std::find(Iter(std::begin(data)), Iter(std::end(data)), CompareT(5));
61       assert(*iter == ArrayT(5));
62       assert(base(iter) == data + 4);
63     }
64 
65     { // some element matches
66       Iter iter = std::find(Iter(arr), Iter(arr + 10), CompareT(6));
67       assert(*iter == ArrayT(6));
68       assert(base(iter) == arr + 5);
69     }
70 
71     { // last element matches
72       Iter iter = std::find(Iter(arr), Iter(arr + 10), CompareT(10));
73       assert(*iter == ArrayT(10));
74       assert(base(iter) == arr + 9);
75     }
76 
77     { // if no element matches, last is returned
78       Iter iter = std::find(Iter(arr), Iter(arr + 10), CompareT(20));
79       assert(base(iter) == arr + 10);
80     }
81 
82     if (!TEST_IS_CONSTANT_EVALUATED)
83       comparable_data.clear();
84   }
85 };
86 
87 template <class IndexT>
88 class Comparable {
89   IndexT index_;
90 
init_index(IndexT i)91   static IndexT init_index(IndexT i) {
92     IndexT size = static_cast<IndexT>(comparable_data.size());
93     comparable_data.push_back(i);
94     return size;
95   }
96 
97 public:
Comparable(IndexT i)98   Comparable(IndexT i) : index_(init_index(i)) {}
99 
operator ==(const Comparable & lhs,const Comparable & rhs)100   friend bool operator==(const Comparable& lhs, const Comparable& rhs) {
101     return comparable_data[lhs.index_] == comparable_data[rhs.index_];
102   }
103 };
104 
105 #if TEST_STD_VER >= 20
106 template <class ElementT>
107 class TriviallyComparable {
108   ElementT el_;
109 
110 public:
TriviallyComparable(ElementT el)111   explicit constexpr TriviallyComparable(ElementT el) : el_(el) {}
112   bool operator==(const TriviallyComparable&) const = default;
113 };
114 #endif
115 
116 template <class CompareT>
117 struct TestTypes {
118   template <class T>
operator ()TestTypes119   TEST_CONSTEXPR_CXX20 void operator()() {
120     types::for_each(types::cpp17_input_iterator_list<T*>(), Test<T, CompareT>());
121   }
122 };
123 
test_deque()124 void test_deque() {
125   { // empty deque
126     std::deque<int> data;
127     assert(std::find(data.begin(), data.end(), 4) == data.end());
128   }
129 
130   { // single element - match
131     std::deque<int> data;
132     data.push_back(4);
133     assert(std::find(data.begin(), data.end(), 4) == data.begin());
134   }
135 
136   { // single element - no match
137     std::deque<int> data;
138     data.push_back(3);
139     assert(std::find(data.begin(), data.end(), 4) == data.end());
140   }
141 
142   // many elements
143   int sizes[] = {2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
144   for (auto size : sizes) {
145     { // last element match
146       std::deque<int> data;
147       data.resize(size);
148       std::fill(data.begin(), data.end(), 3);
149       data[size - 1] = 4;
150       assert(std::find(data.begin(), data.end(), 4) == data.end() - 1);
151     }
152 
153     { // second-last element match
154       std::deque<int> data;
155       data.resize(size);
156       std::fill(data.begin(), data.end(), 3);
157       data[size - 2] = 4;
158       assert(std::find(data.begin(), data.end(), 4) == data.end() - 2);
159     }
160 
161     { // no match
162       std::deque<int> data;
163       data.resize(size);
164       std::fill(data.begin(), data.end(), 3);
165       assert(std::find(data.begin(), data.end(), 4) == data.end());
166     }
167   }
168 }
169 
170 template <class T>
171 struct TestIntegerPromotions1 {
172   template <class U>
testTestIntegerPromotions1173   TEST_CONSTEXPR_CXX20 void test(T val, U to_find) {
174     bool expect_match = val == to_find;
175     assert(std::find(&val, &val + 1, to_find) == (expect_match ? &val : &val + 1));
176   }
177 
178   template <class U>
operator ()TestIntegerPromotions1179   TEST_CONSTEXPR_CXX20 void operator()() {
180     test<U>(0, 0);
181     test<U>(0, 1);
182     test<U>(1, 1);
183     test<U>(0, -1);
184     test<U>(-1, -1);
185     test<U>(0, U(-127));
186     test<U>(T(-127), U(-127));
187     test<U>(T(-128), U(-128));
188     test<U>(T(-129), U(-129));
189     test<U>(T(255), U(255));
190     test<U>(T(256), U(256));
191     test<U>(T(257), U(257));
192     test<U>(0, std::numeric_limits<U>::min());
193     test<U>(T(std::numeric_limits<U>::min()), std::numeric_limits<U>::min());
194     test<U>(0, std::numeric_limits<U>::min() + 1);
195     test<U>(T(std::numeric_limits<U>::min() + 1), std::numeric_limits<U>::min() + 1);
196     test<U>(0, std::numeric_limits<U>::max());
197     test<U>(T(std::numeric_limits<U>::max()), std::numeric_limits<U>::max());
198     test<U>(T(std::numeric_limits<U>::max() - 1), std::numeric_limits<U>::max() - 1);
199   }
200 };
201 
202 struct TestIntegerPromotions {
203   template <class T>
operator ()TestIntegerPromotions204   TEST_CONSTEXPR_CXX20 void operator()() {
205     types::for_each(types::integral_types(), TestIntegerPromotions1<T>());
206   }
207 };
208 
test()209 TEST_CONSTEXPR_CXX20 bool test() {
210   types::for_each(types::integer_types(), TestTypes<char>());
211   types::for_each(types::integer_types(), TestTypes<int>());
212   types::for_each(types::integer_types(), TestTypes<long long>());
213 #if TEST_STD_VER >= 20
214   Test<TriviallyComparable<char>, TriviallyComparable<char>>().operator()<TriviallyComparable<char>*>();
215   Test<TriviallyComparable<wchar_t>, TriviallyComparable<wchar_t>>().operator()<TriviallyComparable<wchar_t>*>();
216 #endif
217 
218   // TODO: Remove the `_LIBCPP_ENABLE_EXPERIMENTAL` check once we have the FTM guarded or views::join isn't
219   // experimental anymore
220 #if TEST_STD_VER >= 20 && (!defined(_LIBCPP_VERSION) || defined(_LIBCPP_ENABLE_EXPERIMENTAL))
221   {
222     std::vector<std::vector<int>> vec = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
223     auto view                         = vec | std::views::join;
224     assert(std::find(view.begin(), view.end(), 4) == std::next(view.begin(), 3));
225   }
226 #endif
227 
228   types::for_each(types::integral_types(), TestIntegerPromotions());
229 
230   return true;
231 }
232 
main(int,char **)233 int main(int, char**) {
234   test_deque();
235   test();
236 #if TEST_STD_VER >= 20
237   static_assert(test());
238 #endif
239 
240   Test<Comparable<char>, Comparable<char> >().operator()<Comparable<char>*>();
241   Test<Comparable<wchar_t>, Comparable<wchar_t> >().operator()<Comparable<wchar_t>*>();
242 
243   return 0;
244 }
245