| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // REQUIRES: has-unix-headers |
| // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20 |
| // UNSUPPORTED: libcpp-hardening-mode=none |
| // XFAIL: availability-verbose_abort-missing |
| |
| // <mdspan> |
| |
| // template<class OtherIndexType> |
| // constexpr mapping(const extents_type& e, const array<OtherIndexType, rank_>& s) noexcept; |
| // |
| // Constraints: |
| // - is_convertible_v<const OtherIndexType&, index_type> is true, and |
| // - is_nothrow_constructible_v<index_type, const OtherIndexType&> is true. |
| // |
| // Preconditions: |
| // - s[i] > 0 is true for all i in the range [0, rank_). |
| // - REQUIRED-SPAN-SIZE(e, s) is representable as a value of type index_type ([basic.fundamental]). |
| // - If rank_ is greater than 0, then there exists a permutation P of the integers in the range [0, rank_), |
| // such that s[pi] >= s[pi_1] * e.extent(pi_1) is true for all i in the range [1, rank_), where |
| // pi is the ith element of P. |
| // [Note 1: For layout_stride, this condition is necessary and sufficient for is_unique() to be true. end note] |
| // |
| // Effects: Direct-non-list-initializes extents_ with e, and for all d in the range [0, rank_), direct-non-list-initializes strides_[d] with as_const(s[d]). |
| |
| #include <mdspan> |
| #include <cassert> |
| |
| #include "check_assertion.h" |
| |
| int main(int, char**) { |
| constexpr size_t D = std::dynamic_extent; |
| |
| // the extents are representable but the product with strides is not, so we can't use it for layout_stride |
| TEST_LIBCPP_ASSERT_FAILURE( |
| ([=] { |
| std::layout_stride::template mapping<std::extents<char, D, 5>> m( |
| std::extents<char, D, 5>(20), std::array<int, 2>{20, 1}); |
| }()), |
| "layout_stride::mapping ctor: required span size is not representable as index_type."); |
| |
| // check that if we first overflow in strides conversion we also fail |
| static_assert(static_cast<unsigned char>(257u) == 1); |
| TEST_LIBCPP_ASSERT_FAILURE( |
| ([=] { |
| std::layout_stride::template mapping<std::extents<unsigned char, D, 5>> m( |
| std::extents<unsigned char, D, 5>(20), std::array<unsigned, 2>{257, 1}); |
| }()), |
| "layout_stride::mapping ctor: required span size is not representable as index_type."); |
| |
| // negative strides are not allowed, check with unsigned index_type so we make sure we catch that |
| TEST_LIBCPP_ASSERT_FAILURE( |
| ([=] { |
| std::layout_stride::template mapping<std::extents<unsigned, D, 5>> m( |
| std::extents<unsigned, D, 5>(20), std::array<int, 2>{20, -1}); |
| }()), |
| "layout_stride::mapping ctor: all strides must be greater than 0"); |
| // zero strides are not allowed, check with unsigned index_type so we make sure we catch that |
| TEST_LIBCPP_ASSERT_FAILURE( |
| ([=] { |
| std::layout_stride::template mapping<std::extents<unsigned, D, 5>> m( |
| std::extents<unsigned, D, 5>(20), std::array<unsigned, 2>{20, 0}); |
| }()), |
| "layout_stride::mapping ctor: all strides must be greater than 0"); |
| return 0; |
| } |