================ @@ -0,0 +1,136 @@ +//===----------------------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23 + +// <span> + +// constexpr reference at(size_type idx) const; // since C++26 + +#include <array> +#include <cassert> +#include <concepts> +#include <span> +#include <stdexcept> +#include <utility> +#include <vector> + +#include "test_macros.h" + +constexpr void testSpanAt(auto span, int idx, int expectedValue) { + // non-const + { + std::same_as<typename decltype(span)::reference> decltype(auto) elem = span.at(idx); + assert(elem == expectedValue); + } + + // const + { + std::same_as<typename decltype(span)::reference> decltype(auto) elem = std::as_const(span).at(idx); + assert(elem == expectedValue); + } +} + +constexpr bool test() { + // With static extent + { + std::array arr{0, 1, 2, 3, 4, 5, 9084}; + std::span arrSpan{arr}; + + assert(std::dynamic_extent != arrSpan.extent); + + testSpanAt(arrSpan, 0, 0); + testSpanAt(arrSpan, 1, 1); + testSpanAt(arrSpan, 6, 9084); + } + + // With dynamic extent + { + std::vector vec{0, 1, 2, 3, 4, 5, 9084}; + std::span vecSpan{vec}; + + assert(std::dynamic_extent == vecSpan.extent); + + testSpanAt(vecSpan, 0, 0); + testSpanAt(vecSpan, 1, 1); + testSpanAt(vecSpan, 6, 9084); + } + + return true; +} + +void test_exceptions() { +#ifndef TEST_HAS_NO_EXCEPTIONS + // With static extent + { + std::array arr{1, 2, 3, 4}; + const std::span arrSpan{arr}; + + try { + TEST_IGNORE_NODISCARD arrSpan.at(arr.size() + 1); ---------------- H-G-Hristov wrote:
C++ Core Guidelines: [ES.48: Avoid casts](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es48-avoid-casts) > Never cast to (void) to ignore a [[nodiscard]]return value. If you > deliberately want to discard such a result, first think hard about whether > that is really a good idea (there is usually a good reason the author of the > function or of the return type used [[nodiscard]] in the first place). If you > still think it's appropriate and your code reviewer agrees, use std::ignore = > to turn off the warning which is simple, portable, and easy to grep. Alternatives ... > - Use std::ignore = to ignore [[nodiscard]] values. Maybe use `std::ignore` instead? https://github.com/llvm/llvm-project/pull/74994 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
