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//===----------------------------------------------------------------------===//
//
// 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
#include <array>
#include <cassert>
#include "test_macros.h"
TEST_CONSTEXPR_CXX17 bool tests()
{
{
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, 0> C;
C c = {};
ASSERT_SAME_TYPE(decltype(c.back()), C::reference);
LIBCPP_ASSERT_NOEXCEPT(c.back());
ASSERT_SAME_TYPE(decltype(c.front()), C::reference);
LIBCPP_ASSERT_NOEXCEPT(c.front());
if (c.size() > (0)) { // always false
TEST_IGNORE_NODISCARD c.front();
TEST_IGNORE_NODISCARD c.back();
}
}
{
typedef double T;
typedef std::array<const T, 0> C;
C c = {};
ASSERT_SAME_TYPE(decltype( c.back()), C::reference);
LIBCPP_ASSERT_NOEXCEPT( c.back());
ASSERT_SAME_TYPE(decltype( c.front()), C::reference);
LIBCPP_ASSERT_NOEXCEPT( c.front());
if (c.size() > (0)) {
TEST_IGNORE_NODISCARD c.front();
TEST_IGNORE_NODISCARD c.back();
}
}
return true;
}
int main(int, char**)
{
tests();
#if TEST_STD_VER >= 17
static_assert(tests(), "");
#endif
return 0;
}
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