//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// <mdspan>
// template<class OtherExtents>
// friend constexpr bool operator==(const mapping& x, const mapping<OtherExtents>& y) noexcept;
// `
// Constraints: extents_type::rank() == OtherExtents::rank() is true.
#include <mdspan>
#include <cassert>
#include <concepts>
#include <span> // dynamic_extent
#include <type_traits>
#include "test_macros.h"
template <class To, class From>
constexpr void test_comparison(bool equal, To dest_exts, From src_exts) {
std::layout_left::mapping<To> dest(dest_exts);
std::layout_left::mapping<From> src(src_exts);
ASSERT_NOEXCEPT(dest == src);
assert((dest == src) == equal);
assert((dest != src) == !equal);
}
struct X {
constexpr bool does_not_match() { return true; }
};
constexpr X compare_layout_mappings(...) { return {}; }
template <class E1, class E2>
constexpr auto compare_layout_mappings(E1 e1, E2 e2)
-> decltype(std::layout_left::mapping<E1>(e1) == std::layout_left::mapping<E2>(e2)) {
return true;
}
template <class T1, class T2>
constexpr void test_comparison_different_rank() {
constexpr size_t D = std::dynamic_extent;
// sanity check same rank
static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, D>(5)));
static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, D>(5)));
static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, 5>()));
static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5>()));
// not equality comparable when rank is not the same
static_assert(compare_layout_mappings(std::extents<T1>(), std::extents<T2, D>(1)).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1>(), std::extents<T2, 1>()).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, D>(1), std::extents<T2>()).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, 1>(), std::extents<T2>()).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, D, D>(5, 5)).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5, D>(5)).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5, 1>()).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, D, D>(5, 5), std::extents<T2, D>(5)).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, 5, D>(5), std::extents<T2, D>(5)).does_not_match());
static_assert(compare_layout_mappings(std::extents<T1, 5, 5>(), std::extents<T2, 5>()).does_not_match());
}
template <class T1, class T2>
constexpr void test_comparison_same_rank() {
constexpr size_t D = std::dynamic_extent;
test_comparison(true, std::extents<T1>(), std::extents<T2>());
test_comparison(true, std::extents<T1, D>(5), std::extents<T2, D>(5));
test_comparison(true, std::extents<T1, 5>(), std::extents<T2, D>(5));
test_comparison(true, std::extents<T1, D>(5), std::extents<T2, 5>());
test_comparison(true, std::extents<T1, 5>(), std::extents< T2, 5>());
test_comparison(false, std::extents<T1, D>(5), std::extents<T2, D>(7));
test_comparison(false, std::extents<T1, 5>(), std::extents<T2, D>(7));
test_comparison(false, std::extents<T1, D>(5), std::extents<T2, 7>());
test_comparison(false, std::extents<T1, 5>(), std::extents<T2, 7>());
test_comparison(true, std::extents<T1, D, D, D, D, D>(5, 6, 7, 8, 9), std::extents<T2, D, D, D, D, D>(5, 6, 7, 8, 9));
test_comparison(true, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 8, 9>(6, 7));
test_comparison(true, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 8, 9>());
test_comparison(
false, std::extents<T1, D, D, D, D, D>(5, 6, 7, 8, 9), std::extents<T2, D, D, D, D, D>(5, 6, 3, 8, 9));
test_comparison(false, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 3, 9>(6, 7));
test_comparison(false, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 3, 9>());
}
template <class T1, class T2>
constexpr void test_comparison() {
test_comparison_same_rank<T1, T2>();
test_comparison_different_rank<T1, T2>();
}
constexpr bool test() {
test_comparison<int, int>();
test_comparison<int, size_t>();
test_comparison<size_t, int>();
test_comparison<size_t, long>();
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}