libcxx/test/std/containers/sequences/array/size_and_alignment.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 // template <class T, size_t N >
  12 // struct array
  13
  14 // Test the size and alignment matches that of an array of a given type.
  15
  16 #include <array>
  17 #include <iterator>
  18 #include <type_traits>
  19 #include <cstddef>
  20
  21 #include "test_macros.h"
  22
  23
  24 template <class T, size_t Size>
  25 struct MyArray {
  26   T elems[Size];
  27 };
  28
  29 template <class T, size_t Size>
  30 void test() {
  31   typedef T CArrayT[Size == 0 ? 1 : Size];
  32   typedef std::array<T, Size> ArrayT;
  33   typedef MyArray<T, Size == 0 ? 1 : Size> MyArrayT;
  34   static_assert(sizeof(ArrayT) == sizeof(CArrayT), "");
  35   static_assert(sizeof(ArrayT) == sizeof(MyArrayT), "");
  36   static_assert(TEST_ALIGNOF(ArrayT) == TEST_ALIGNOF(MyArrayT), "");
  37 #if defined(_LIBCPP_VERSION)
  38   ArrayT a;
  39   ((void)a);
  40   static_assert(sizeof(ArrayT) == sizeof(a.__elems_), "");
  41   static_assert(TEST_ALIGNOF(ArrayT) == __alignof__(a.__elems_), "");
  42 #endif
  43 }
  44
  45 template <class T>
  46 void test_type() {
  47   test<T, 1>();
  48   test<T, 42>();
  49   test<T, 0>();
  50 }
  51
  52 struct TEST_ALIGNAS(TEST_ALIGNOF(std::max_align_t) * 2) TestType1 {
  53
  54 };
  55
  56 struct TEST_ALIGNAS(TEST_ALIGNOF(std::max_align_t) * 2) TestType2 {
  57   char data[1000];
  58 };
  59
  60 //static_assert(sizeof(void*) == 4, "");
  61
  62 int main(int, char**) {
  63   test_type<char>();
  64   test_type<int>();
  65   test_type<double>();
  66   test_type<long double>();
  67   test_type<std::max_align_t>();
  68   test_type<TestType1>();
  69   test_type<TestType2>();
  70
  71   return 0;
  72 }