libcxx/test/std/numerics/numeric.ops/numeric.ops.sat/div_sat.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 T>
  14 // constexpr T div_sat(T x, T y) noexcept;                     // freestanding
  15
  16 #include <concepts>
  17 #include <numeric>
  18 #include <type_traits>
  19
  20 #include "test_macros.h"
  21
  22 // Constraints
  23
  24 template <typename T, typename U>
  25 concept CanDo = requires(T x, U y) {
  26   { std::div_sat(x, y) } -> std::same_as<T>;
  27 };
  28
  29 template <typename T, typename U>
  30 constexpr void test_constraint_success() {
  31   static_assert(CanDo<T, T>);
  32   static_assert(!CanDo<U, T>);
  33   static_assert(!CanDo<T, U>);
  34 }
  35
  36 template <typename T>
  37 constexpr void test_constraint_fail() {
  38   using I = int;
  39   static_assert(!CanDo<T, T>);
  40   static_assert(!CanDo<I, T>);
  41   static_assert(!CanDo<T, I>);
  42 }
  43
  44 constexpr void test() {
  45   // Contraint success - Signed
  46   using SI = long long int;
  47   test_constraint_success<signed char, SI>();
  48   test_constraint_success<short int, SI>();
  49   test_constraint_success<signed char, SI>();
  50   test_constraint_success<short int, SI>();
  51   test_constraint_success<int, SI>();
  52   test_constraint_success<long int, SI>();
  53   test_constraint_success<long long int, int>();
  54 #ifndef TEST_HAS_NO_INT128
  55   test_constraint_success<__int128_t, SI>();
  56 #endif
  57   // Contraint success - Unsigned
  58   using UI = unsigned long long int;
  59   test_constraint_success<unsigned char, UI>();
  60   test_constraint_success<unsigned short int, UI>();
  61   test_constraint_success<unsigned int, UI>();
  62   test_constraint_success<unsigned long int, UI>();
  63   test_constraint_success<unsigned long long int, unsigned int>();
  64 #ifndef TEST_HAS_NO_INT128
  65   test_constraint_success<__uint128_t, UI>();
  66 #endif
  67
  68   // Contraint failure
  69   test_constraint_fail<bool>();
  70   test_constraint_fail<char>();
  71 #ifndef TEST_HAS_NO_INT128
  72   test_constraint_fail<wchar_t>();
  73 #endif
  74   test_constraint_fail<char8_t>();
  75   test_constraint_fail<char16_t>();
  76   test_constraint_fail<char32_t>();
  77   test_constraint_fail<float>();
  78   test_constraint_fail<double>();
  79   test_constraint_fail<long double>();
  80 }
  81
  82 //  A function call expression that violates the precondition in the Preconditions: element is not a core constant expression (7.7 [expr.const]).
  83
  84 template <auto N>
  85 using QuotT = std::integral_constant<decltype(N), std::div_sat(N, N)>;
  86
  87 template <auto N>
  88 QuotT<N> div_by_zero();
  89
  90 template <auto N>
  91 concept CanDivByZero = requires { div_by_zero<N>(); };
  92
  93 static_assert(!CanDivByZero<static_cast<signed char>(0)>);
  94 static_assert(!CanDivByZero<static_cast<short int>(0)>);
  95 static_assert(!CanDivByZero<0>);
  96 static_assert(!CanDivByZero<0L>);
  97 static_assert(!CanDivByZero<0LL>);
  98 #ifndef TEST_HAS_NO_INT128
  99 static_assert(!CanDivByZero<static_cast<__int128_t>(0)>);
 100 #endif
 101 static_assert(!CanDivByZero<static_cast<unsigned char>(0)>);
 102 static_assert(!CanDivByZero<static_cast<unsigned short int>(0)>);
 103 static_assert(!CanDivByZero<0U>);
 104 static_assert(!CanDivByZero<0UL>);
 105 static_assert(!CanDivByZero<0ULL>);
 106 #ifndef TEST_HAS_NO_INT128
 107 static_assert(!CanDivByZero<static_cast<__uint128_t>(0)>);
 108 #endif