| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <array> |
| |
| // reference front(); // constexpr in C++17 |
| // reference back(); // constexpr in C++17 |
| // const_reference front(); // constexpr in C++14 |
| // const_reference back(); // constexpr in C++14 |
| |
| #include <array> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| // std::array is explicitly allowed to be initialized with A a = { init-list };. |
| // Disable the missing braces warning for this reason. |
| #include "disable_missing_braces_warning.h" |
| |
| #if TEST_STD_VER > 14 |
| constexpr bool check_front( double val ) |
| { |
| std::array<double, 3> arr = {1, 2, 3.5}; |
| return arr.front() == val; |
| } |
| |
| constexpr bool check_back( double val ) |
| { |
| std::array<double, 3> arr = {1, 2, 3.5}; |
| return arr.back() == val; |
| } |
| #endif |
| |
| int main(int, char**) |
| { |
| { |
| typedef double T; |
| typedef std::array<T, 3> C; |
| C c = {1, 2, 3.5}; |
| |
| C::reference r1 = c.front(); |
| assert(r1 == 1); |
| r1 = 5.5; |
| assert(c[0] == 5.5); |
| |
| C::reference r2 = c.back(); |
| assert(r2 == 3.5); |
| r2 = 7.5; |
| assert(c[2] == 7.5); |
| } |
| { |
| typedef double T; |
| typedef std::array<T, 3> C; |
| const C c = {1, 2, 3.5}; |
| C::const_reference r1 = c.front(); |
| assert(r1 == 1); |
| |
| C::const_reference r2 = c.back(); |
| assert(r2 == 3.5); |
| } |
| { |
| typedef double T; |
| typedef std::array<T, 0> C; |
| C c = {}; |
| C const& cc = c; |
| ASSERT_SAME_TYPE(decltype( c.back()), typename C::reference); |
| ASSERT_SAME_TYPE(decltype(cc.back()), typename C::const_reference); |
| LIBCPP_ASSERT_NOEXCEPT( c.back()); |
| LIBCPP_ASSERT_NOEXCEPT( cc.back()); |
| ASSERT_SAME_TYPE(decltype( c.front()), typename C::reference); |
| ASSERT_SAME_TYPE(decltype(cc.front()), typename C::const_reference); |
| LIBCPP_ASSERT_NOEXCEPT( c.front()); |
| LIBCPP_ASSERT_NOEXCEPT( cc.front()); |
| if (c.size() > (0)) { // always false |
| TEST_IGNORE_NODISCARD c.front(); |
| TEST_IGNORE_NODISCARD c.back(); |
| TEST_IGNORE_NODISCARD cc.front(); |
| TEST_IGNORE_NODISCARD cc.back(); |
| } |
| } |
| { |
| typedef double T; |
| typedef std::array<const T, 0> C; |
| C c = {{}}; |
| C const& cc = c; |
| ASSERT_SAME_TYPE(decltype( c.back()), typename C::reference); |
| ASSERT_SAME_TYPE(decltype(cc.back()), typename C::const_reference); |
| LIBCPP_ASSERT_NOEXCEPT( c.back()); |
| LIBCPP_ASSERT_NOEXCEPT( cc.back()); |
| ASSERT_SAME_TYPE(decltype( c.front()), typename C::reference); |
| ASSERT_SAME_TYPE(decltype(cc.front()), typename C::const_reference); |
| LIBCPP_ASSERT_NOEXCEPT( c.front()); |
| LIBCPP_ASSERT_NOEXCEPT( cc.front()); |
| if (c.size() > (0)) { |
| TEST_IGNORE_NODISCARD c.front(); |
| TEST_IGNORE_NODISCARD c.back(); |
| TEST_IGNORE_NODISCARD cc.front(); |
| TEST_IGNORE_NODISCARD cc.back(); |
| } |
| } |
| #if TEST_STD_VER > 11 |
| { |
| typedef double T; |
| typedef std::array<T, 3> C; |
| constexpr C c = {1, 2, 3.5}; |
| |
| constexpr T t1 = c.front(); |
| static_assert (t1 == 1, ""); |
| |
| constexpr T t2 = c.back(); |
| static_assert (t2 == 3.5, ""); |
| } |
| #endif |
| |
| #if TEST_STD_VER > 14 |
| { |
| static_assert (check_front(1), ""); |
| static_assert (check_back (3.5), ""); |
| } |
| #endif |
| |
| return 0; |
| } |