libcxx/test/std/containers/views/mdspan/layout_right/comparison.pass.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-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 //   friend constexpr bool operator==(const mapping& x, const mapping<OtherExtents>& y) noexcept;
  15 //                                      `
  16 // Constraints: extents_type::rank() == OtherExtents::rank() is true.
  17
  18 #include <mdspan>
  19 #include <type_traits>
  20 #include <concepts>
  21 #include <cassert>
  22
  23 #include "test_macros.h"
  24
  25 template <class To, class From>
  26 constexpr void test_comparison(bool equal, To dest_exts, From src_exts) {
  27   std::layout_right::mapping<To> dest(dest_exts);
  28   std::layout_right::mapping<From> src(src_exts);
  29   ASSERT_NOEXCEPT(dest == src);
  30   assert((dest == src) == equal);
  31   assert((dest != src) == !equal);
  32 }
  33
  34 struct X {
  35   constexpr bool does_not_match() { return true; }
  36 };
  37
  38 constexpr X compare_layout_mappings(...) { return {}; }
  39
  40 template <class E1, class E2>
  41 constexpr auto compare_layout_mappings(E1 e1, E2 e2)
  42     -> decltype(std::layout_right::mapping<E1>(e1) == std::layout_right::mapping<E2>(e2)) {
  43   return true;
  44 }
  45
  46 template <class T1, class T2>
  47 constexpr void test_comparison_different_rank() {
  48   constexpr size_t D = std::dynamic_extent;
  49
  50   // sanity check same rank
  51   static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, D>(5)));
  52   static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, D>(5)));
  53   static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, 5>()));
  54   static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5>()));
  55
  56   // not equality comparable when rank is not the same
  57   static_assert(compare_layout_mappings(std::extents<T1>(), std::extents<T2, D>(1)).does_not_match());
  58   static_assert(compare_layout_mappings(std::extents<T1>(), std::extents<T2, 1>()).does_not_match());
  59
  60   static_assert(compare_layout_mappings(std::extents<T1, D>(1), std::extents<T2>()).does_not_match());
  61   static_assert(compare_layout_mappings(std::extents<T1, 1>(), std::extents<T2>()).does_not_match());
  62
  63   static_assert(compare_layout_mappings(std::extents<T1, D>(5), std::extents<T2, D, D>(5, 5)).does_not_match());
  64   static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5, D>(5)).does_not_match());
  65   static_assert(compare_layout_mappings(std::extents<T1, 5>(), std::extents<T2, 5, 1>()).does_not_match());
  66
  67   static_assert(compare_layout_mappings(std::extents<T1, D, D>(5, 5), std::extents<T2, D>(5)).does_not_match());
  68   static_assert(compare_layout_mappings(std::extents<T1, 5, D>(5), std::extents<T2, D>(5)).does_not_match());
  69   static_assert(compare_layout_mappings(std::extents<T1, 5, 5>(), std::extents<T2, 5>()).does_not_match());
  70 }
  71
  72 template <class T1, class T2>
  73 constexpr void test_comparison_same_rank() {
  74   constexpr size_t D = std::dynamic_extent;
  75
  76   test_comparison(true, std::extents<T1>(), std::extents<T2>());
  77
  78   test_comparison(true, std::extents<T1, D>(5), std::extents<T2, D>(5));
  79   test_comparison(true, std::extents<T1, 5>(), std::extents<T2, D>(5));
  80   test_comparison(true, std::extents<T1, D>(5), std::extents<T2, 5>());
  81   test_comparison(true, std::extents<T1, 5>(), std::extents< T2, 5>());
  82   test_comparison(false, std::extents<T1, D>(5), std::extents<T2, D>(7));
  83   test_comparison(false, std::extents<T1, 5>(), std::extents<T2, D>(7));
  84   test_comparison(false, std::extents<T1, D>(5), std::extents<T2, 7>());
  85   test_comparison(false, std::extents<T1, 5>(), std::extents<T2, 7>());
  86
  87   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));
  88   test_comparison(true, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 8, 9>(6, 7));
  89   test_comparison(true, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 8, 9>());
  90   test_comparison(
  91       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));
  92   test_comparison(false, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 3, 9>(6, 7));
  93   test_comparison(false, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 3, 9>());
  94 }
  95
  96 template <class T1, class T2>
  97 constexpr void test_comparison() {
  98   test_comparison_same_rank<T1, T2>();
  99   test_comparison_different_rank<T1, T2>();
 100 }
 101
 102 constexpr bool test() {
 103   test_comparison<int, int>();
 104   test_comparison<int, size_t>();
 105   test_comparison<size_t, int>();
 106   test_comparison<size_t, long>();
 107   return true;
 108 }
 109
 110 int main(int, char**) {
 111   test();
 112   static_assert(test());
 113   return 0;
 114 }