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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <array>
// reference operator[] (size_type)
// const_reference operator[] (size_type); // constexpr in C++14
// reference at (size_type)
// const_reference at (size_type); // 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_idx( size_t idx, double val )
{
std::array<double, 3> arr = {1, 2, 3.5};
return arr[idx] == val;
}
#endif
int main()
{
{
typedef double T;
typedef std::array<T, 3> C;
C c = {1, 2, 3.5};
C::reference r1 = c[0];
assert(r1 == 1);
r1 = 5.5;
assert(c.front() == 5.5);
C::reference r2 = c[2];
assert(r2 == 3.5);
r2 = 7.5;
assert(c.back() == 7.5);
}
{
typedef double T;
typedef std::array<T, 3> C;
const C c = {1, 2, 3.5};
C::const_reference r1 = c[0];
assert(r1 == 1);
C::const_reference r2 = c[2];
assert(r2 == 3.5);
}
{ // Test operator[] "works" on zero sized arrays
typedef double T;
typedef std::array<T, 0> C;
C c = {};
C const& cc = c;
static_assert((std::is_same<decltype(c[0]), T &>::value), "");
static_assert((std::is_same<decltype(cc[0]), const T &>::value), "");
if (c.size() > (0)) { // always false
C::reference r1 = c[0];
C::const_reference r2 = cc[0];
((void)r1);
((void)r2);
}
}
{ // Test operator[] "works" on zero sized arrays
typedef double T;
typedef std::array<const T, 0> C;
C c = {{}};
C const& cc = c;
static_assert((std::is_same<decltype(c[0]), const T &>::value), "");
static_assert((std::is_same<decltype(cc[0]), const T &>::value), "");
if (c.size() > (0)) { // always false
C::reference r1 = c[0];
C::const_reference r2 = cc[0];
((void)r1);
((void)r2);
}
}
#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[0];
static_assert (t1 == 1, "");
constexpr T t2 = c[2];
static_assert (t2 == 3.5, "");
}
#endif
#if TEST_STD_VER > 14
{
static_assert (check_idx(0, 1), "");
static_assert (check_idx(1, 2), "");
static_assert (check_idx(2, 3.5), "");
}
#endif
}
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