133 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// A type M meets the layout mapping requirements if14// - M models copyable and equality_comparable,15// - is_nothrow_move_constructible_v<M> is true,16// - is_nothrow_move_assignable_v<M> is true,17// - is_nothrow_swappable_v<M> is true, and18//19// the following types and expressions are well-formed and have the specified semantics.20//21// typename M::extents_type22// Result: A type that is a specialization of extents.23//24// typename M::index_type25// Result: typename M::extents_type::index_type.26//27// typename M::rank_type28// Result: typename M::extents_type::rank_type.29//30// typename M::layout_type31// Result: A type MP that meets the layout mapping policy requirements ([mdspan.layout.policy.reqmts]) and for which is-mapping-of<MP, M> is true.32//33// m.extents()34// Result: const typename M::extents_type&35//36// m(i...)37// Result: typename M::index_type38// Returns: A nonnegative integer less than numeric_limits<typename M::index_type>::max() and less than or equal to numeric_limits<size_t>::max().39//40// m(i...) == m(static_cast<typename M::index_type>(i)...)41// Result: bool42// Returns: true43//44// m.required_span_size()45// Result: typename M::index_type46// Returns: If the size of the multidimensional index space m.extents() is 0, then 0, else 1 plus the maximum value of m(i...) for all i.47//48// m.is_unique()49// Result: bool50// Returns: true only if for every i and j where (i != j || ...) is true, m(i...) != m(j...) is true.51//52// m.is_exhaustive()53// Result: bool54// Returns: true only if for all k in the range [0, m.required_span_size()) there exists an i such that m(i...) equals k.55//56// m.is_strided()57// Result: bool58// Returns: true only if for every rank index r of m.extents() there exists an integer59// sr such that, for all i where (i+dr) is a multidimensional index in m.extents() ([mdspan.overview]),60// m((i + dr)...) - m(i...) equals sr61//62// m.stride(r)63// Preconditions: m.is_strided() is true.64// Result: typename M::index_type65// Returns: sr as defined in m.is_strided() above.66//67// M::is_always_unique()68// Result: A constant expression ([expr.const]) of type bool.69// Returns: true only if m.is_unique() is true for all possible objects m of type M.70//71// M::is_always_exhaustive()72// Result: A constant expression ([expr.const]) of type bool.73// Returns: true only if m.is_exhaustive() is true for all possible objects m of type M.74//75// M::is_always_strided()76// Result: A constant expression ([expr.const]) of type bool.77// Returns: true only if m.is_strided() is true for all possible objects m of type M.78 79#include <cassert>80#include <cstddef>81#include <mdspan>82#include <type_traits>83#include <utility>84 85#include "test_macros.h"86 87// Common requirements of all layout mappings88template <class M, size_t... Idxs>89void test_mapping_requirements(std::index_sequence<Idxs...>) {90 using E = typename M::extents_type;91 LIBCPP_STATIC_ASSERT(std::__mdspan_detail::__is_extents_v<E>);92 static_assert(std::is_copy_constructible_v<M>);93 static_assert(std::is_nothrow_move_constructible_v<M>);94 static_assert(std::is_nothrow_move_assignable_v<M>);95 static_assert(std::is_nothrow_swappable_v<M>);96 ASSERT_SAME_TYPE(typename M::index_type, typename E::index_type);97 ASSERT_SAME_TYPE(typename M::size_type, typename E::size_type);98 ASSERT_SAME_TYPE(typename M::rank_type, typename E::rank_type);99 ASSERT_SAME_TYPE(typename M::layout_type, std::layout_left);100 ASSERT_SAME_TYPE(typename M::layout_type::template mapping<E>, M);101 static_assert(std::is_same_v<decltype(std::declval<M>().extents()), const E&>);102 static_assert(std::is_same_v<decltype(std::declval<M>()(Idxs...)), typename M::index_type>);103 static_assert(std::is_same_v<decltype(std::declval<M>().required_span_size()), typename M::index_type>);104 static_assert(std::is_same_v<decltype(std::declval<M>().is_unique()), bool>);105 static_assert(std::is_same_v<decltype(std::declval<M>().is_exhaustive()), bool>);106 static_assert(std::is_same_v<decltype(std::declval<M>().is_strided()), bool>);107 if constexpr (E::rank() > 0)108 static_assert(std::is_same_v<decltype(std::declval<M>().stride(0)), typename M::index_type>);109 static_assert(std::is_same_v<decltype(M::is_always_unique()), bool>);110 static_assert(std::is_same_v<decltype(M::is_always_exhaustive()), bool>);111 static_assert(std::is_same_v<decltype(M::is_always_strided()), bool>);112}113 114template <class L, class E>115void test_layout_mapping_requirements() {116 using M = typename L::template mapping<E>;117 test_mapping_requirements<M>(std::make_index_sequence<E::rank()>());118}119 120template <class E>121void test_layout_mapping_left() {122 test_layout_mapping_requirements<std::layout_left, E>();123}124 125int main(int, char**) {126 constexpr size_t D = std::dynamic_extent;127 test_layout_mapping_left<std::extents<int>>();128 test_layout_mapping_left<std::extents<signed char, 4, 5>>();129 test_layout_mapping_left<std::extents<unsigned, D, 4>>();130 test_layout_mapping_left<std::extents<size_t, D, D, D, D>>();131 return 0;132}133