libcxx/test/std/numerics/numeric.ops/numeric.ops.sat/saturate_cast.compile.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, c++23
  10
  11 // <numeric>
  12
  13 // template<class R, class T>
  14 //   constexpr R saturate_cast(T x) noexcept;                    // freestanding
  15
  16 #include <concepts>
  17 #include <numeric>
  18
  19 #include "test_macros.h"
  20
  21 template <typename R, typename T>
  22 concept CanDo = requires(T x) {
  23   { std::saturate_cast<R>(x) } -> std::same_as<R>;
  24 };
  25
  26 template <typename R, typename T>
  27 constexpr void test_constraint_success() {
  28   static_assert(CanDo<R, T>);
  29   static_assert(CanDo<T, T>);
  30   static_assert(CanDo<T, R>);
  31 }
  32
  33 template <typename T>
  34 constexpr void test_constraint_fail() {
  35   using I = int;
  36   using R = T;
  37   static_assert(!CanDo<R, T>);
  38   static_assert(!CanDo<T, R>);
  39   static_assert(!CanDo<I, T>);
  40   static_assert(!CanDo<T, I>);
  41 }
  42
  43 constexpr void test() {
  44   // Contraint success - Signed
  45   using SI = long long int;
  46   test_constraint_success<SI, signed char>();
  47   test_constraint_success<SI, short int>();
  48   test_constraint_success<SI, signed char>();
  49   test_constraint_success<SI, short int>();
  50   test_constraint_success<SI, int>();
  51   test_constraint_success<SI, long int>();
  52   test_constraint_success<int, long long int>();
  53 #ifndef TEST_HAS_NO_INT128
  54   test_constraint_success<__int128_t, SI>();
  55 #endif
  56   // Contraint success - Unsigned
  57   using UI = unsigned long long int;
  58   test_constraint_success<UI, unsigned char>();
  59   test_constraint_success<UI, unsigned short int>();
  60   test_constraint_success<UI, unsigned int>();
  61   test_constraint_success<UI, unsigned long int>();
  62   test_constraint_success<unsigned int, unsigned long long int>();
  63 #ifndef TEST_HAS_NO_INT128
  64   test_constraint_success<UI, __uint128_t>();
  65 #endif
  66
  67   // Contraint failure
  68   test_constraint_fail<bool>();
  69   test_constraint_fail<char>();
  70 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  71   test_constraint_fail<wchar_t>();
  72 #endif
  73   test_constraint_fail<char8_t>();
  74   test_constraint_fail<char16_t>();
  75   test_constraint_fail<char32_t>();
  76   test_constraint_fail<float>();
  77   test_constraint_fail<double>();
  78   test_constraint_fail<long double>();
  79 }