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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
10
11// <mdspan>
12
13// template<class OtherExtents>
14// constexpr explicit(extents_type::rank() > 0)
15// mapping(const layout_stride::mapping<OtherExtents>& other);
16//
17// Constraints: is_constructible_v<extents_type, OtherExtents> is true.
18//
19// Preconditions:
20// - If extents_type::rank() > 0 is true, then for all r in the range [0, extents_type::rank()),
21// other.stride(r) equals other.extents().fwd-prod-of-extents(r), and
22// - other.required_span_size() is representable as a value of type index_type ([basic.fundamental]).
23//
24// Effects: Direct-non-list-initializes extents_ with other.extents().
25
26#include <mdspan>
27#include <type_traits>
28#include <cassert>
29#include <limits>
30
31#include "test_macros.h"
32
33template <bool implicit, class ToE, class FromE>
34constexpr void test_conversion(FromE src_exts) {
35 using To = std::layout_left::mapping<ToE>;
36 using From = std::layout_stride::mapping<FromE>;
37 std::array<typename FromE::index_type, FromE::rank()> strides;
38 if constexpr (FromE::rank() > 0) {
39 strides[0] = 1;
40 for (size_t r = 1; r < FromE::rank(); r++)
41 strides[r] = src_exts.extent(r - 1) * strides[r - 1];
42 }
43 From src(src_exts, strides);
44
45 ASSERT_NOEXCEPT(To(src));
46 To dest(src);
47 assert(dest == src);
48
49 if constexpr (implicit) {
50 To dest_implicit = src;
51 assert(dest_implicit == src);
52 } else {
53 assert((!std::is_convertible_v<From, To>));
54 }
55}
56
57template <class T1, class T2>
58constexpr void test_conversion() {
59 constexpr size_t D = std::dynamic_extent;
60
61 // clang-format off
62 test_conversion<true, std::extents<T1>>(std::extents<T2>());
63 test_conversion<false, std::extents<T1, D>>(std::extents<T2, D>(5));
64 test_conversion<false, std::extents<T1, 5>>(std::extents<T2, D>(5));
65 test_conversion<false, std::extents<T1, 5>>(std::extents<T2, 5>());
66 test_conversion<false, std::extents<T1, 5, D>>(std::extents<T2, D, D>(5, 5));
67 test_conversion<false, std::extents<T1, D, D>>(std::extents<T2, D, D>(5, 5));
68 test_conversion<false, std::extents<T1, D, D>>(std::extents<T2, D, 7>(5));
69 test_conversion<false, std::extents<T1, 5, 7>>(std::extents<T2, 5, 7>());
70 test_conversion<false, std::extents<T1, 5, D, 8, D, D>>(std::extents<T2, D, D, 8, 9, 1>(5, 7));
71 test_conversion<false, std::extents<T1, D, D, D, D, D>>(
72 std::extents<T2, D, D, D, D, D>(5, 7, 8, 9, 1));
73 test_conversion<false, std::extents<T1, D, D, 8, 9, D>>(std::extents<T2, D, 7, 8, 9, 1>(5));
74 test_conversion<false, std::extents<T1, 5, 7, 8, 9, 1>>(std::extents<T2, 5, 7, 8, 9, 1>());
75 // clang-format on
76}
77
78template <class IdxT, size_t... Extents>
79using ll_mapping_t = std::layout_left::mapping<std::extents<IdxT, Extents...>>;
80template <class IdxT, size_t... Extents>
81using ls_mapping_t = std::layout_stride::mapping<std::extents<IdxT, Extents...>>;
82
83constexpr void test_rank_mismatch() {
84 constexpr size_t D = std::dynamic_extent;
85
86 static_assert(!std::is_constructible_v<ll_mapping_t<int, D>, ls_mapping_t<int>>);
87 static_assert(!std::is_constructible_v<ll_mapping_t<int>, ls_mapping_t<int, D, D>>);
88 static_assert(!std::is_constructible_v<ll_mapping_t<int, D>, ls_mapping_t<int, D, D>>);
89 static_assert(!std::is_constructible_v<ll_mapping_t<int, D, D, D>, ls_mapping_t<int, D, D>>);
90}
91
92constexpr void test_static_extent_mismatch() {
93 constexpr size_t D = std::dynamic_extent;
94
95 static_assert(!std::is_constructible_v<ll_mapping_t<int, D, 5>, ls_mapping_t<int, D, 4>>);
96 static_assert(!std::is_constructible_v<ll_mapping_t<int, 5>, ls_mapping_t<int, 4>>);
97 static_assert(!std::is_constructible_v<ll_mapping_t<int, 5, D>, ls_mapping_t<int, 4, D>>);
98}
99
100constexpr bool test() {
101 test_conversion<int, int>();
102 test_conversion<int, size_t>();
103 test_conversion<size_t, int>();
104 test_conversion<size_t, long>();
105 test_rank_mismatch();
106 test_static_extent_mismatch();
107 return true;
108}
109
110int main(int, char**) {
111 test();
112 static_assert(test());
113 return 0;
114}
115

source code of libcxx/test/std/containers/views/mdspan/layout_left/ctor.layout_stride.pass.cpp