libcxx/test/std/containers/sequences/array/array.data/data_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 T* data() const;
  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 int main(int, char**)
  28 {
  29     {
  30         typedef double T;
  31         typedef std::array<T, 3> C;
  32         const C c = {1, 2, 3.5};
  33         const T* p = c.data();
  34         assert(p[0] == 1);
  35         assert(p[1] == 2);
  36         assert(p[2] == 3.5);
  37     }
  38     {
  39         typedef double T;
  40         typedef std::array<T, 0> C;
  41         const C c = {};
  42         const T* p = c.data();
  43         (void)p; // to placate scan-build
  44     }
  45     {
  46       typedef NoDefault T;
  47       typedef std::array<T, 0> C;
  48       const C c = {};
  49       const T* p = c.data();
  50       LIBCPP_ASSERT(p != nullptr);
  51     }
  52     {
  53       typedef std::max_align_t T;
  54       typedef std::array<T, 0> C;
  55       const C c = {};
  56       const T* p = c.data();
  57       LIBCPP_ASSERT(p != nullptr);
  58       std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
  59       assert(pint % TEST_ALIGNOF(std::max_align_t) == 0);
  60     }
  61 #if TEST_STD_VER > 14
  62     {
  63         typedef std::array<int, 5> C;
  64         constexpr C c1{0,1,2,3,4};
  65         constexpr const C c2{0,1,2,3,4};
  66
  67         static_assert (  c1.data()  == &c1[0], "");
  68         static_assert ( *c1.data()  ==  c1[0], "");
  69         static_assert (  c2.data()  == &c2[0], "");
  70         static_assert ( *c2.data()  ==  c2[0], "");
  71     }
  72 #endif
  73
  74   return 0;
  75 }