fcaccf817d
This patch adds std::extents. extents is one of the core classes used by std::mdspan. It describes a multi-dimensional index space with a mix of compile time and runtime sizes. Furthermore, it is templated on the index type used to describe the multi-dimensional index space. The class is designed to be highly optimizable in performance critical code sections, and is fully useable in constant expressions contexts. Testing of this class tends to be somewhat combinatorical, due to the large number of possible corner cases involved in situations where we have both runtime and compile time extents. To add to this, the class is designed to be interoperable (in particular constructible) from arguments which only need to be convertible to the index_type, but are otherwise arbitrary user types. For a larger discussion on the design of this class refer to: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0009r18.html Co-authored-by: Damien L-G <dalg24@gmail.com> Reviewed By: ldionne, #libc Spies: libcxx-commits, H-G-Hristov, tschuett, philnik, arichardson, Mordante, crtrott Differential Revision: https://reviews.llvm.org/D148067
96 lines
3.7 KiB
C++
96 lines
3.7 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
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// <mdspan>
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//
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// template<class OtherIndexType, size_t... OtherExtents>
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// friend constexpr bool operator==(const extents& lhs,
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// const extents<OtherIndexType, OtherExtents...>& rhs) noexcept;
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//
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// Returns: true if lhs.rank() equals rhs.rank() and
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// if lhs.extent(r) equals rhs.extent(r) for every rank index r of rhs, otherwise false.
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//
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#include <mdspan>
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#include <type_traits>
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#include <concepts>
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#include <cassert>
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#include "test_macros.h"
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template <class To, class From>
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constexpr void test_comparison(bool equal, To dest, From src) {
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ASSERT_NOEXCEPT(dest == src);
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assert((dest == src) == equal);
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assert((dest != src) == !equal);
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}
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template <class T1, class T2>
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constexpr void test_comparison_different_rank() {
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constexpr size_t D = std::dynamic_extent;
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test_comparison(false, std::extents<T1>(), std::extents<T2, D>(1));
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test_comparison(false, std::extents<T1>(), std::extents<T2, 1>());
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test_comparison(false, std::extents<T1, D>(1), std::extents<T2>());
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test_comparison(false, std::extents<T1, 1>(), std::extents<T2>());
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test_comparison(false, std::extents<T1, D>(5), std::extents<T2, D, D>(5, 5));
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test_comparison(false, std::extents<T1, 5>(), std::extents<T2, 5, D>(5));
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test_comparison(false, std::extents<T1, 5>(), std::extents<T2, 5, 1>());
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test_comparison(false, std::extents<T1, D, D>(5, 5), std::extents<T2, D>(5));
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test_comparison(false, std::extents<T1, 5, D>(5), std::extents<T2, D>(5));
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test_comparison(false, std::extents<T1, 5, 5>(), std::extents<T2, 5>());
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}
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template <class T1, class T2>
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constexpr void test_comparison_same_rank() {
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constexpr size_t D = std::dynamic_extent;
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test_comparison(true, std::extents<T1>(), std::extents<T2>());
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test_comparison(true, std::extents<T1, D>(5), std::extents<T2, D>(5));
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test_comparison(true, std::extents<T1, 5>(), std::extents<T2, D>(5));
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test_comparison(true, std::extents<T1, D>(5), std::extents<T2, 5>());
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test_comparison(true, std::extents<T1, 5>(), std::extents< T2, 5>());
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test_comparison(false, std::extents<T1, D>(5), std::extents<T2, D>(7));
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test_comparison(false, std::extents<T1, 5>(), std::extents<T2, D>(7));
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test_comparison(false, std::extents<T1, D>(5), std::extents<T2, 7>());
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test_comparison(false, std::extents<T1, 5>(), std::extents<T2, 7>());
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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));
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test_comparison(true, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 8, 9>(6, 7));
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test_comparison(true, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 8, 9>());
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test_comparison(
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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));
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test_comparison(false, std::extents<T1, D, 6, D, 8, D>(5, 7, 9), std::extents<T2, 5, D, D, 3, 9>(6, 7));
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test_comparison(false, std::extents<T1, 5, 6, 7, 8, 9>(5, 6, 7, 8, 9), std::extents<T2, 5, 6, 7, 3, 9>());
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}
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template <class T1, class T2>
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constexpr void test_comparison() {
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test_comparison_same_rank<T1, T2>();
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test_comparison_different_rank<T1, T2>();
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}
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constexpr bool test() {
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test_comparison<int, int>();
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test_comparison<int, size_t>();
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test_comparison<size_t, int>();
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test_comparison<size_t, long>();
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return true;
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}
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int main(int, char**) {
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test();
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static_assert(test());
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return 0;
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}
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