libcxx/test/std/containers/sequences/array/indexing_const.pass.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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <array>
  10
  11 // const_reference operator[](size_type) const; // constexpr in C++14
  12 // Libc++ marks it as noexcept
  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         LIBCPP_ASSERT_NOEXCEPT(c[0]);
  26         ASSERT_SAME_TYPE(C::const_reference, decltype(c[0]));
  27         C::const_reference r1 = c[0];
  28         assert(r1 == 1);
  29         C::const_reference r2 = c[2];
  30         assert(r2 == 3.5);
  31     }
  32     // Test operator[] "works" on zero sized arrays
  33     {
  34         {
  35             typedef double T;
  36             typedef std::array<T, 0> C;
  37             C const c = {};
  38             LIBCPP_ASSERT_NOEXCEPT(c[0]);
  39             ASSERT_SAME_TYPE(C::const_reference, decltype(c[0]));
  40             if (c.size() > (0)) { // always false
  41                 C::const_reference r = c[0];
  42                 (void)r;
  43             }
  44         }
  45         {
  46             typedef double T;
  47             typedef std::array<T const, 0> C;
  48             C const c = {};
  49             LIBCPP_ASSERT_NOEXCEPT(c[0]);
  50             ASSERT_SAME_TYPE(C::const_reference, decltype(c[0]));
  51             if (c.size() > (0)) { // always false
  52               C::const_reference r = c[0];
  53               (void)r;
  54             }
  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 }