libcxx/test/std/containers/sequences/array/array.data/data.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 // T *data();
  12
  13 #include <array>
  14 #include <cassert>
  15 #include <cstddef>       // for std::max_align_t
  16
  17 #include "test_macros.h"
  18
  19 // std::array is explicitly allowed to be initialized with A a = { init-list };.
  20 // Disable the missing braces warning for this reason.
  21 #include "disable_missing_braces_warning.h"
  22
  23 struct NoDefault {
  24   NoDefault(int) {}
  25 };
  26
  27
  28 int main(int, char**)
  29 {
  30     {
  31         typedef double T;
  32         typedef std::array<T, 3> C;
  33         C c = {1, 2, 3.5};
  34         T* p = c.data();
  35         assert(p[0] == 1);
  36         assert(p[1] == 2);
  37         assert(p[2] == 3.5);
  38     }
  39     {
  40         typedef double T;
  41         typedef std::array<T, 0> C;
  42         C c = {};
  43         T* p = c.data();
  44         LIBCPP_ASSERT(p != nullptr);
  45     }
  46     {
  47       typedef double T;
  48       typedef std::array<const T, 0> C;
  49       C c = {{}};
  50       const T* p = c.data();
  51       static_assert((std::is_same<decltype(c.data()), const T*>::value), "");
  52       LIBCPP_ASSERT(p != nullptr);
  53     }
  54   {
  55       typedef std::max_align_t T;
  56       typedef std::array<T, 0> C;
  57       const C c = {};
  58       const T* p = c.data();
  59       LIBCPP_ASSERT(p != nullptr);
  60       std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
  61       assert(pint % TEST_ALIGNOF(std::max_align_t) == 0);
  62     }
  63     {
  64       typedef NoDefault T;
  65       typedef std::array<T, 0> C;
  66       C c = {};
  67       T* p = c.data();
  68       LIBCPP_ASSERT(p != nullptr);
  69     }
  70
  71   return 0;
  72 }