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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // <array> 10 11 // const_reference front() const; // constexpr in C++14 12 // const_reference back() const; // constexpr in C++14 13 14 #include <array> 15 #include <cassert> 16 17 #include "test_macros.h" 18 19 TEST_CONSTEXPR_CXX14 bool tests() 20 { 21 { 22 typedef double T; 23 typedef std::array<T, 3> C; 24 C const c = {1, 2, 3.5}; 25 C::const_reference r1 = c.front(); 26 assert(r1 == 1); 27 28 C::const_reference r2 = c.back(); 29 assert(r2 == 3.5); 30 } 31 { 32 typedef double T; 33 typedef std::array<T, 0> C; 34 C const c = {}; 35 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference); 36 LIBCPP_ASSERT_NOEXCEPT(c.back()); 37 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference); 38 LIBCPP_ASSERT_NOEXCEPT(c.front()); 39 if (c.size() > (0)) { // always false 40 TEST_IGNORE_NODISCARD c.front(); 41 TEST_IGNORE_NODISCARD c.back(); 42 } 43 } 44 { 45 typedef double T; 46 typedef std::array<const T, 0> C; 47 C const c = {}; 48 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference); 49 LIBCPP_ASSERT_NOEXCEPT(c.back()); 50 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference); 51 LIBCPP_ASSERT_NOEXCEPT(c.front()); 52 if (c.size() > (0)) { 53 TEST_IGNORE_NODISCARD c.front(); 54 TEST_IGNORE_NODISCARD c.back(); 55 } 56 } 57 58 return true; 59 } 60 61 int main(int, char**) 62 { 63 tests(); 64 #if TEST_STD_VER >= 14 65 static_assert(tests(), ""); 66 #endif 67 return 0; 68 } 69