67 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// <array>10 11// const_reference front() const; // constexpr in C++1412// const_reference back() const; // constexpr in C++1413 14#include <array>15#include <cassert>16 17#include "test_macros.h"18 19TEST_CONSTEXPR_CXX14 bool tests() {20 {21 typedef double T;22 typedef std::array<T, 3> C;23 C const c = {1, 2, 3.5};24 C::const_reference r1 = c.front();25 assert(r1 == 1);26 27 C::const_reference r2 = c.back();28 assert(r2 == 3.5);29 }30 {31 typedef double T;32 typedef std::array<T, 0> C;33 C const c = {};34 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference);35 LIBCPP_ASSERT_NOEXCEPT(c.back());36 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference);37 LIBCPP_ASSERT_NOEXCEPT(c.front());38 if (c.size() > (0)) { // always false39 TEST_IGNORE_NODISCARD c.front();40 TEST_IGNORE_NODISCARD c.back();41 }42 }43 {44 typedef double T;45 typedef std::array<const T, 0> C;46 C const c = {};47 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference);48 LIBCPP_ASSERT_NOEXCEPT(c.back());49 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference);50 LIBCPP_ASSERT_NOEXCEPT(c.front());51 if (c.size() > (0)) {52 TEST_IGNORE_NODISCARD c.front();53 TEST_IGNORE_NODISCARD c.back();54 }55 }56 57 return true;58}59 60int main(int, char**) {61 tests();62#if TEST_STD_VER >= 1463 static_assert(tests(), "");64#endif65 return 0;66}67