//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <algorithm>
// UNSUPPORTED: c++03, c++11, c++14, c++17
// template<input_iterator I, sentinel_for<I> S, class Proj = identity,
// indirect_unary_predicate<projected<I, Proj>> Pred>
// constexpr I ranges::find_if(I first, S last, Pred pred, Proj proj = {});
// template<input_range R, class Proj = identity,
// indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
// constexpr borrowed_iterator_t<R>
// ranges::find_if(R&& r, Pred pred, Proj proj = {});
#include <algorithm>
#include <array>
#include <cassert>
#include <ranges>
#include "almost_satisfies_types.h"
#include "test_iterators.h"
struct Predicate {
bool operator()(int);
};
template <class It, class Sent = It>
concept HasFindIfIt = requires(It it, Sent sent) { std::ranges::find_if(it, sent, Predicate{}); };
static_assert(HasFindIfIt<int*>);
static_assert(!HasFindIfIt<InputIteratorNotDerivedFrom>);
static_assert(!HasFindIfIt<InputIteratorNotIndirectlyReadable>);
static_assert(!HasFindIfIt<InputIteratorNotInputOrOutputIterator>);
static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
static_assert(!HasFindIfIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
static_assert(!HasFindIfIt<int*, int>);
static_assert(!HasFindIfIt<int, int*>);
template <class Pred>
concept HasFindIfPred = requires(int* it, Pred pred) {std::ranges::find_if(it, it, pred); };
static_assert(!HasFindIfPred<IndirectUnaryPredicateNotCopyConstructible>);
static_assert(!HasFindIfPred<IndirectUnaryPredicateNotPredicate>);
template <class R>
concept HasFindIfR = requires(R r) { std::ranges::find_if(r, Predicate{}); };
static_assert(HasFindIfR<std::array<int, 0>>);
static_assert(!HasFindIfR<int>);
static_assert(!HasFindIfR<InputRangeNotDerivedFrom>);
static_assert(!HasFindIfR<InputRangeNotIndirectlyReadable>);
static_assert(!HasFindIfR<InputRangeNotInputOrOutputIterator>);
static_assert(!HasFindIfR<InputRangeNotSentinelSemiregular>);
static_assert(!HasFindIfR<InputRangeNotSentinelEqualityComparableWith>);
template <class It, class Sent = It>
constexpr void test_iterators() {
{
int a[] = {1, 2, 3, 4};
std::same_as<It> auto ret = std::ranges::find_if(It(a), Sent(It(a + 4)), [](int x) mutable { return x == 4; });
assert(base(ret) == a + 3);
assert(*ret == 4);
}
{
int a[] = {1, 2, 3, 4};
auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));
std::same_as<It> auto ret = std::ranges::find_if(range, [](int x) mutable { return x == 4; });
assert(base(ret) == a + 3);
assert(*ret == 4);
}
}
struct NonConstComparable {
friend constexpr bool operator==(const NonConstComparable&, const NonConstComparable&) { return false; }
friend constexpr bool operator==(NonConstComparable&, NonConstComparable&) { return false; }
friend constexpr bool operator==(const NonConstComparable&, NonConstComparable&) { return false; }
friend constexpr bool operator==(NonConstComparable&, const NonConstComparable&) { return true; }
};
constexpr bool test() {
test_iterators<int*>();
test_iterators<const int*>();
test_iterators<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
test_iterators<bidirectional_iterator<int*>>();
test_iterators<forward_iterator<int*>>();
test_iterators<random_access_iterator<int*>>();
test_iterators<contiguous_iterator<int*>>();
{
// check that projections are used properly and that they are called with the iterator directly
{
int a[] = {1, 2, 3, 4};
auto ret = std::ranges::find_if(a, a + 4, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; });
assert(ret == a + 3);
}
{
int a[] = {1, 2, 3, 4};
auto ret = std::ranges::find_if(a, [&](int* i) { return i == a + 3; }, [](int& i) { return &i; });
assert(ret == a + 3);
}
}
{
// check that the first element is returned
{
struct S {
int comp;
int other;
};
S a[] = { {0, 0}, {0, 2}, {0, 1} };
auto ret = std::ranges::find_if(a, [](int i){ return i == 0; }, &S::comp);
assert(ret == a);
assert(ret->comp == 0);
assert(ret->other == 0);
}
{
struct S {
int comp;
int other;
};
S a[] = { {0, 0}, {0, 2}, {0, 1} };
auto ret = std::ranges::find_if(a, a + 3, [](int i) { return i == 0; }, &S::comp);
assert(ret == a);
assert(ret->comp == 0);
assert(ret->other == 0);
}
}
{
// check that end + 1 iterator is returned with no match
{
int a[] = {1, 1, 1};
auto ret = std::ranges::find_if(a, a + 3, [](int) { return false; });
assert(ret == a + 3);
}
{
int a[] = {1, 1, 1};
auto ret = std::ranges::find_if(a, [](int){ return false; });
assert(ret == a + 3);
}
}
{
// check that ranges::dangling is returned
[[maybe_unused]] std::same_as<std::ranges::dangling> auto ret =
std::ranges::find_if(std::array{1, 2}, [](int){ return false; });
}
{
// check that an iterator is returned with a borrowing range
int a[] = {1, 2, 3, 4};
std::same_as<int*> auto ret = std::ranges::find_if(std::views::all(a), [](int){ return true; });
assert(ret == a);
assert(*ret == 1);
}
{
// check that std::invoke is used
struct S { int i; };
S a[] = { S{1}, S{3}, S{2} };
std::same_as<S*> auto ret = std::ranges::find_if(a, [](int) { return false; }, &S::i);
assert(ret == a + 3);
}
{
// count projection and predicate invocation count
{
int a[] = {1, 2, 3, 4};
int predicate_count = 0;
int projection_count = 0;
auto ret = std::ranges::find_if(a, a + 4,
[&](int i) { ++predicate_count; return i == 2; },
[&](int i) { ++projection_count; return i; });
assert(ret == a + 1);
assert(*ret == 2);
assert(predicate_count == 2);
assert(projection_count == 2);
}
{
int a[] = {1, 2, 3, 4};
int predicate_count = 0;
int projection_count = 0;
auto ret = std::ranges::find_if(a,
[&](int i) { ++predicate_count; return i == 2; },
[&](int i) { ++projection_count; return i; });
assert(ret == a + 1);
assert(*ret == 2);
assert(predicate_count == 2);
assert(projection_count == 2);
}
}
{
// check that the return type of `iter::operator*` doesn't change
{
NonConstComparable a[] = { NonConstComparable{} };
auto ret = std::ranges::find_if(a, a + 1, [](auto&& e) { return e == NonConstComparable{}; });
assert(ret == a);
}
{
NonConstComparable a[] = { NonConstComparable{} };
auto ret = std::ranges::find_if(a, [](auto&& e) { return e == NonConstComparable{}; });
assert(ret == a);
}
}
{
// check that an empty range works
{
std::array<int ,0> a = {};
auto ret = std::ranges::find_if(a.begin(), a.end(), [](int) { return true; });
assert(ret == a.begin());
}
{
std::array<int, 0> a = {};
auto ret = std::ranges::find_if(a, [](int) { return true; });
assert(ret == a.begin());
}
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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