235 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// <algorithm>10 11// UNSUPPORTED: c++03, c++11, c++14, c++1712 13// template<input_iterator I, sentinel_for<I> S, class Proj = identity,14// indirect_unary_predicate<projected<I, Proj>> Pred>15// constexpr I ranges::find_if(I first, S last, Pred pred, Proj proj = {});16// template<input_range R, class Proj = identity,17// indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>18// constexpr borrowed_iterator_t<R>19// ranges::find_if(R&& r, Pred pred, Proj proj = {});20 21#include <algorithm>22#include <array>23#include <cassert>24#include <ranges>25 26#include "almost_satisfies_types.h"27#include "test_iterators.h"28 29struct Predicate {30 bool operator()(int);31};32 33template <class It, class Sent = It>34concept HasFindIfIt = requires(It it, Sent sent) { std::ranges::find_if(it, sent, Predicate{}); };35static_assert(HasFindIfIt<int*>);36static_assert(!HasFindIfIt<InputIteratorNotDerivedFrom>);37static_assert(!HasFindIfIt<InputIteratorNotIndirectlyReadable>);38static_assert(!HasFindIfIt<InputIteratorNotInputOrOutputIterator>);39static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);40static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);41 42static_assert(!HasFindIfIt<int*, int>);43static_assert(!HasFindIfIt<int, int*>);44 45template <class Pred>46concept HasFindIfPred = requires(int* it, Pred pred) {std::ranges::find_if(it, it, pred); };47 48static_assert(!HasFindIfPred<IndirectUnaryPredicateNotCopyConstructible>);49static_assert(!HasFindIfPred<IndirectUnaryPredicateNotPredicate>);50 51template <class R>52concept HasFindIfR = requires(R r) { std::ranges::find_if(r, Predicate{}); };53static_assert(HasFindIfR<std::array<int, 0>>);54static_assert(!HasFindIfR<int>);55static_assert(!HasFindIfR<InputRangeNotDerivedFrom>);56static_assert(!HasFindIfR<InputRangeNotIndirectlyReadable>);57static_assert(!HasFindIfR<InputRangeNotInputOrOutputIterator>);58static_assert(!HasFindIfR<InputRangeNotSentinelSemiregular>);59static_assert(!HasFindIfR<InputRangeNotSentinelEqualityComparableWith>);60 61template <class It, class Sent = It>62constexpr void test_iterators() {63 {64 int a[] = {1, 2, 3, 4};65 std::same_as<It> auto ret = std::ranges::find_if(It(a), Sent(It(a + 4)), [](int x) mutable { return x == 4; });66 assert(base(ret) == a + 3);67 assert(*ret == 4);68 }69 {70 int a[] = {1, 2, 3, 4};71 auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));72 std::same_as<It> auto ret = std::ranges::find_if(range, [](int x) mutable { return x == 4; });73 assert(base(ret) == a + 3);74 assert(*ret == 4);75 }76}77 78struct NonConstComparable {79 friend constexpr bool operator==(const NonConstComparable&, const NonConstComparable&) { return false; }80 friend constexpr bool operator==(NonConstComparable&, NonConstComparable&) { return false; }81 friend constexpr bool operator==(const NonConstComparable&, NonConstComparable&) { return false; }82 friend constexpr bool operator==(NonConstComparable&, const NonConstComparable&) { return true; }83};84 85constexpr bool test() {86 test_iterators<int*>();87 test_iterators<const int*>();88 test_iterators<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();89 test_iterators<bidirectional_iterator<int*>>();90 test_iterators<forward_iterator<int*>>();91 test_iterators<random_access_iterator<int*>>();92 test_iterators<contiguous_iterator<int*>>();93 94 {95 // check that projections are used properly and that they are called with the iterator directly96 {97 int a[] = {1, 2, 3, 4};98 auto ret = std::ranges::find_if(a, a + 4, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; });99 assert(ret == a + 3);100 }101 {102 int a[] = {1, 2, 3, 4};103 auto ret = std::ranges::find_if(a, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; });104 assert(ret == a + 3);105 }106 }107 108 {109 // check that the first element is returned110 {111 struct S {112 int comp;113 int other;114 };115 S a[] = { {0, 0}, {0, 2}, {0, 1} };116 auto ret = std::ranges::find_if(a, [](int i){ return i == 0; }, &S::comp);117 assert(ret == a);118 assert(ret->comp == 0);119 assert(ret->other == 0);120 }121 {122 struct S {123 int comp;124 int other;125 };126 S a[] = { {0, 0}, {0, 2}, {0, 1} };127 auto ret = std::ranges::find_if(a, a + 3, [](int i) { return i == 0; }, &S::comp);128 assert(ret == a);129 assert(ret->comp == 0);130 assert(ret->other == 0);131 }132 }133 134 {135 // check that end + 1 iterator is returned with no match136 {137 int a[] = {1, 1, 1};138 auto ret = std::ranges::find_if(a, a + 3, [](int) { return false; });139 assert(ret == a + 3);140 }141 {142 int a[] = {1, 1, 1};143 auto ret = std::ranges::find_if(a, [](int){ return false; });144 assert(ret == a + 3);145 }146 }147 148 {149 // check that ranges::dangling is returned150 [[maybe_unused]] std::same_as<std::ranges::dangling> auto ret =151 std::ranges::find_if(std::array{1, 2}, [](int){ return false; });152 }153 154 {155 // check that an iterator is returned with a borrowing range156 int a[] = {1, 2, 3, 4};157 std::same_as<int*> auto ret = std::ranges::find_if(std::views::all(a), [](int){ return true; });158 assert(ret == a);159 assert(*ret == 1);160 }161 162 {163 // check that std::invoke is used164 struct S { int i; };165 S a[] = { S{1}, S{3}, S{2} };166 std::same_as<S*> auto ret = std::ranges::find_if(a, [](int) { return false; }, &S::i);167 assert(ret == a + 3);168 }169 170 {171 // count projection and predicate invocation count172 {173 int a[] = {1, 2, 3, 4};174 int predicate_count = 0;175 int projection_count = 0;176 auto ret = std::ranges::find_if(a, a + 4,177 [&](int i) { ++predicate_count; return i == 2; },178 [&](int i) { ++projection_count; return i; });179 assert(ret == a + 1);180 assert(*ret == 2);181 assert(predicate_count == 2);182 assert(projection_count == 2);183 }184 {185 int a[] = {1, 2, 3, 4};186 int predicate_count = 0;187 int projection_count = 0;188 auto ret = std::ranges::find_if(a,189 [&](int i) { ++predicate_count; return i == 2; },190 [&](int i) { ++projection_count; return i; });191 assert(ret == a + 1);192 assert(*ret == 2);193 assert(predicate_count == 2);194 assert(projection_count == 2);195 }196 }197 198 {199 // check that the return type of `iter::operator*` doesn't change200 {201 NonConstComparable a[] = { NonConstComparable{} };202 auto ret = std::ranges::find_if(a, a + 1, [](auto&& e) { return e == NonConstComparable{}; });203 assert(ret == a);204 }205 {206 NonConstComparable a[] = { NonConstComparable{} };207 auto ret = std::ranges::find_if(a, [](auto&& e) { return e == NonConstComparable{}; });208 assert(ret == a);209 }210 }211 212 {213 // check that an empty range works214 {215 std::array<int ,0> a = {};216 auto ret = std::ranges::find_if(a.begin(), a.end(), [](int) { return true; });217 assert(ret == a.begin());218 }219 {220 std::array<int, 0> a = {};221 auto ret = std::ranges::find_if(a, [](int) { return true; });222 assert(ret == a.begin());223 }224 }225 226 return true;227}228 229int main(int, char**) {230 test();231 static_assert(test());232 233 return 0;234}235