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 #include <cstdint>
  17
  18 #include "test_macros.h"
  19
  20 struct NoDefault {
  21     TEST_CONSTEXPR NoDefault(int) { }
  22 };
  23
  24 #if TEST_STD_VER < 11
  25 struct natural_alignment {
  26     long t1;
  27     long long t2;
  28     double t3;
  29     long double t4;
  30 };
  31 #endif
  32
  33 TEST_CONSTEXPR_CXX17 bool tests()
  34 {
  35     {
  36         typedef double T;
  37         typedef std::array<T, 3> C;
  38         C c = {1, 2, 3.5};
  39         ASSERT_NOEXCEPT(c.data());
  40         T* p = c.data();
  41         assert(p[0] == 1);
  42         assert(p[1] == 2);
  43         assert(p[2] == 3.5);
  44     }
  45     {
  46         typedef double T;
  47         typedef std::array<T, 0> C;
  48         C c = {};
  49         ASSERT_NOEXCEPT(c.data());
  50         T* p = c.data();
  51         (void)p;
  52     }
  53     {
  54         typedef double T;
  55         typedef std::array<const T, 0> C;
  56         C c = {{}};
  57         ASSERT_NOEXCEPT(c.data());
  58         const T* p = c.data();
  59         (void)p;
  60         static_assert((std::is_same<decltype(c.data()), const T*>::value), "");
  61     }
  62     {
  63         typedef NoDefault T;
  64         typedef std::array<T, 0> C;
  65         C c = {};
  66         ASSERT_NOEXCEPT(c.data());
  67         T* p = c.data();
  68         (void)p;
  69     }
  70     {
  71         std::array<int, 5> c = {0, 1, 2, 3, 4};
  72         assert(c.data() == &c[0]);
  73         assert(*c.data() == c[0]);
  74     }
  75
  76     return true;
  77 }
  78
  79 int main(int, char**)
  80 {
  81     tests();
  82 #if TEST_STD_VER >= 17
  83     static_assert(tests(), "");
  84 #endif
  85
  86     // Test the alignment of data()
  87     {
  88 #if TEST_STD_VER < 11
  89         typedef natural_alignment T;
  90 #else
  91         typedef std::max_align_t T;
  92 #endif
  93         typedef std::array<T, 0> C;
  94         const C c = {};
  95         const T* p = c.data();
  96         std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
  97         assert(pint % TEST_ALIGNOF(T) == 0);
  98     }
  99     return 0;
 100 }