libcxx/test/std/numerics/bit/byteswap.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 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
  10
  11 #include <bit>
  12 #include <cassert>
  13 #include <cstdint>
  14 #include <utility>
  15
  16 #include "test_macros.h"
  17
  18 template <class T>
  19 concept has_byteswap = requires(T t) {
  20   std::byteswap(t);
  21 };
  22
  23 static_assert(!has_byteswap<void*>);
  24 static_assert(!has_byteswap<float>);
  25 static_assert(!has_byteswap<char[2]>);
  26 static_assert(!has_byteswap<std::byte>);
  27
  28 template <class T>
  29 constexpr void test_num(T in, T expected) {
  30   assert(std::byteswap(in) == expected);
  31   ASSERT_SAME_TYPE(decltype(std::byteswap(in)), decltype(in));
  32   ASSERT_NOEXCEPT(std::byteswap(in));
  33 }
  34
  35 template <class T>
  36 constexpr std::pair<T, T> get_test_data() {
  37   switch (sizeof(T)) {
  38   case 2:
  39     return {static_cast<T>(0x1234), static_cast<T>(0x3412)};
  40   case 4:
  41     return {static_cast<T>(0x60AF8503), static_cast<T>(0x0385AF60)};
  42   case 8:
  43     return {static_cast<T>(0xABCDFE9477936406), static_cast<T>(0x0664937794FECDAB)};
  44   default:
  45     assert(false);
  46     return {}; // for MSVC, whose `assert` is tragically not [[noreturn]]
  47   }
  48 }
  49
  50 template <class T>
  51 constexpr void test_implementation_defined_size() {
  52   const auto [in, expected] = get_test_data<T>();
  53   test_num<T>(in, expected);
  54 }
  55
  56 constexpr bool test() {
  57   test_num<std::uint8_t>(0xAB, 0xAB);
  58   test_num<std::uint16_t>(0xCDEF, 0xEFCD);
  59   test_num<std::uint32_t>(0x01234567, 0x67452301);
  60   test_num<std::uint64_t>(0x0123456789ABCDEF, 0xEFCDAB8967452301);
  61
  62   test_num<std::int8_t>(static_cast<std::int8_t>(0xAB), static_cast<std::int8_t>(0xAB));
  63   test_num<std::int16_t>(static_cast<std::int16_t>(0xCDEF), static_cast<std::int16_t>(0xEFCD));
  64   test_num<std::int32_t>(0x01234567, 0x67452301);
  65   test_num<std::int64_t>(0x0123456789ABCDEF, 0xEFCDAB8967452301);
  66
  67 #ifndef TEST_HAS_NO_INT128
  68   const auto in = static_cast<__uint128_t>(0x0123456789ABCDEF) << 64 | 0x13579BDF02468ACE;
  69   const auto expected = static_cast<__uint128_t>(0xCE8A4602DF9B5713) << 64 | 0xEFCDAB8967452301;
  70   test_num<__uint128_t>(in, expected);
  71   test_num<__int128_t>(in, expected);
  72 #endif
  73
  74   test_num<bool>(true, true);
  75   test_num<bool>(false, false);
  76   test_num<char>(static_cast<char>(0xCD), static_cast<char>(0xCD));
  77   test_num<unsigned char>(0xEF, 0xEF);
  78   test_num<signed char>(0x45, 0x45);
  79   test_num<char8_t>(0xAB, 0xAB);
  80   test_num<char16_t>(0xABCD, 0xCDAB);
  81   test_num<char32_t>(0xABCDEF01, 0x01EFCDAB);
  82 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  83   test_implementation_defined_size<wchar_t>();
  84 #endif
  85
  86   test_implementation_defined_size<short>();
  87   test_implementation_defined_size<unsigned short>();
  88   test_implementation_defined_size<int>();
  89   test_implementation_defined_size<unsigned int>();
  90   test_implementation_defined_size<long>();
  91   test_implementation_defined_size<unsigned long>();
  92   test_implementation_defined_size<long long>();
  93   test_implementation_defined_size<unsigned long long>();
  94   return true;
  95 }
  96
  97 int main(int, char**) {
  98   test();
  99   static_assert(test());
 100
 101   return 0;
 102 }