138 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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++2010 11// <mdspan>12 13// template<class OtherExtents>14// constexpr explicit(!is_convertible_v<OtherExtents, extents_type>)15// mapping(const mapping<OtherExtents>&) noexcept;16 17// Constraints: is_constructible_v<extents_type, OtherExtents> is true.18//19// Preconditions: other.required_span_size() is representable as a value of type index_type20 21#include <cassert>22#include <cstddef>23#include <limits>24#include <mdspan>25#include <type_traits>26 27#include "test_macros.h"28 29template <class To, class From>30constexpr void test_implicit_conversion(To dest, From src) {31 assert(dest == src);32}33 34template <bool implicit, class ToE, class FromE>35constexpr void test_conversion(FromE src_exts) {36 using To = std::layout_left::mapping<ToE>;37 using From = std::layout_left::mapping<FromE>;38 From src(src_exts);39 40 ASSERT_NOEXCEPT(To(src));41 To dest(src);42 43 assert(dest == src);44 if constexpr (implicit) {45 dest = src;46 assert(dest == src);47 test_implicit_conversion<To, From>(src, src);48 }49}50 51template <class T1, class T2>52constexpr void test_conversion() {53 constexpr size_t D = std::dynamic_extent;54 constexpr bool idx_convertible =55 static_cast<size_t>(std::numeric_limits<T1>::max()) >= static_cast<size_t>(std::numeric_limits<T2>::max());56 57 // clang-format off58 test_conversion<idx_convertible && true, std::extents<T1>>(std::extents<T2>());59 test_conversion<idx_convertible && true, std::extents<T1, D>>(std::extents<T2, D>(5));60 test_conversion<idx_convertible && false, std::extents<T1, 5>>(std::extents<T2, D>(5));61 test_conversion<idx_convertible && true, std::extents<T1, 5>>(std::extents<T2, 5>());62 test_conversion<idx_convertible && false, std::extents<T1, 5, D>>(std::extents<T2, D, D>(5, 5));63 test_conversion<idx_convertible && true, std::extents<T1, D, D>>(std::extents<T2, D, D>(5, 5));64 test_conversion<idx_convertible && true, std::extents<T1, D, D>>(std::extents<T2, D, 7>(5));65 test_conversion<idx_convertible && true, std::extents<T1, 5, 7>>(std::extents<T2, 5, 7>());66 test_conversion<idx_convertible && false, std::extents<T1, 5, D, 8, D, D>>(std::extents<T2, D, D, 8, 9, 1>(5, 7));67 test_conversion<idx_convertible && true, std::extents<T1, D, D, D, D, D>>(68 std::extents<T2, D, D, D, D, D>(5, 7, 8, 9, 1));69 test_conversion<idx_convertible && true, std::extents<T1, D, D, 8, 9, D>>(std::extents<T2, D, 7, 8, 9, 1>(5));70 test_conversion<idx_convertible && true, std::extents<T1, 5, 7, 8, 9, 1>>(std::extents<T2, 5, 7, 8, 9, 1>());71 // clang-format on72}73 74template <class IdxT, size_t... Extents>75using mapping_t = std::layout_left::mapping<std::extents<IdxT, Extents...>>;76 77constexpr void test_no_implicit_conversion() {78 constexpr size_t D = std::dynamic_extent;79 80 // Sanity check that one static to dynamic conversion works81 static_assert(std::is_constructible_v<mapping_t<int, D>, mapping_t<int, 5>>);82 static_assert(std::is_convertible_v<mapping_t<int, 5>, mapping_t<int, D>>);83 84 // Check that dynamic to static conversion only works explicitly85 static_assert(std::is_constructible_v<mapping_t<int, 5>, mapping_t<int, D>>);86 static_assert(!std::is_convertible_v<mapping_t<int, D>, mapping_t<int, 5>>);87 88 // Sanity check that one static to dynamic conversion works89 static_assert(std::is_constructible_v<mapping_t<int, D, 7>, mapping_t<int, 5, 7>>);90 static_assert(std::is_convertible_v<mapping_t<int, 5, 7>, mapping_t<int, D, 7>>);91 92 // Check that dynamic to static conversion only works explicitly93 static_assert(std::is_constructible_v<mapping_t<int, 5, 7>, mapping_t<int, D, 7>>);94 static_assert(!std::is_convertible_v<mapping_t<int, D, 7>, mapping_t<int, 5, 7>>);95 96 // Sanity check that smaller index_type to larger index_type conversion works97 static_assert(std::is_constructible_v<mapping_t<size_t, 5>, mapping_t<int, 5>>);98 static_assert(std::is_convertible_v<mapping_t<int, 5>, mapping_t<size_t, 5>>);99 100 // Check that larger index_type to smaller index_type conversion works explicitly only101 static_assert(std::is_constructible_v<mapping_t<int, 5>, mapping_t<size_t, 5>>);102 static_assert(!std::is_convertible_v<mapping_t<size_t, 5>, mapping_t<int, 5>>);103}104 105constexpr void test_rank_mismatch() {106 constexpr size_t D = std::dynamic_extent;107 108 static_assert(!std::is_constructible_v<mapping_t<int, D>, mapping_t<int>>);109 static_assert(!std::is_constructible_v<mapping_t<int>, mapping_t<int, D, D>>);110 static_assert(!std::is_constructible_v<mapping_t<int, D>, mapping_t<int, D, D>>);111 static_assert(!std::is_constructible_v<mapping_t<int, D, D, D>, mapping_t<int, D, D>>);112}113 114constexpr void test_static_extent_mismatch() {115 constexpr size_t D = std::dynamic_extent;116 117 static_assert(!std::is_constructible_v<mapping_t<int, D, 5>, mapping_t<int, D, 4>>);118 static_assert(!std::is_constructible_v<mapping_t<int, 5>, mapping_t<int, 4>>);119 static_assert(!std::is_constructible_v<mapping_t<int, 5, D>, mapping_t<int, 4, D>>);120}121 122constexpr bool test() {123 test_conversion<int, int>();124 test_conversion<int, size_t>();125 test_conversion<size_t, int>();126 test_conversion<size_t, long>();127 test_no_implicit_conversion();128 test_rank_mismatch();129 test_static_extent_mismatch();130 return true;131}132 133int main(int, char**) {134 test();135 static_assert(test());136 return 0;137}138