1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <numeric> 12 13 // template<class _M, class _N> 14 // constexpr common_type_t<_M,_N> gcd(_M __m, _N __n) 15 16 #include <numeric> 17 #include <cassert> 18 #include <cstdlib> // for rand() 19 #include <iostream> 20 21 constexpr struct { 22 int x; 23 int y; 24 int expect; 25 } Cases[] = { 26 {0, 0, 0}, 27 {1, 0, 1}, 28 {0, 1, 1}, 29 {1, 1, 1}, 30 {2, 3, 1}, 31 {2, 4, 2}, 32 {36, 17, 1}, 33 {36, 18, 18} 34 }; 35 36 37 template <typename Input1, typename Input2, typename Output> 38 constexpr bool test0(Input1 in1, Input2 in2, Output out) 39 { 40 static_assert((std::is_same<Output, decltype(std::gcd(in1, in2))>::value), "" ); 41 static_assert((std::is_same<Output, decltype(std::gcd(in2, in1))>::value), "" ); 42 return out == std::gcd(in1, in2) ? true : (std::abort(), false); 43 } 44 45 46 template <typename Input1, typename Input2 = Input1> 47 constexpr bool do_test(int dummy = 0) 48 { 49 using S1 = typename std::make_signed<Input1>::type; 50 using S2 = typename std::make_signed<Input2>::type; 51 using U1 = typename std::make_unsigned<Input1>::type; 52 using U2 = typename std::make_unsigned<Input2>::type; 53 bool accumulate = true; 54 for (auto TC : Cases) { 55 { // Test with two signed types 56 using Output = std::common_type_t<S1, S2>; 57 accumulate &= test0<S1, S2, Output>(TC.x, TC.y, TC.expect); 58 accumulate &= test0<S1, S2, Output>(-TC.x, TC.y, TC.expect); 59 accumulate &= test0<S1, S2, Output>(TC.x, -TC.y, TC.expect); 60 accumulate &= test0<S1, S2, Output>(-TC.x, -TC.y, TC.expect); 61 accumulate &= test0<S2, S1, Output>(TC.x, TC.y, TC.expect); 62 accumulate &= test0<S2, S1, Output>(-TC.x, TC.y, TC.expect); 63 accumulate &= test0<S2, S1, Output>(TC.x, -TC.y, TC.expect); 64 accumulate &= test0<S2, S1, Output>(-TC.x, -TC.y, TC.expect); 65 } 66 { // test with two unsigned types 67 using Output = std::common_type_t<U1, U2>; 68 accumulate &= test0<U1, U2, Output>(TC.x, TC.y, TC.expect); 69 accumulate &= test0<U2, U1, Output>(TC.x, TC.y, TC.expect); 70 } 71 { // Test with mixed signs 72 using Output = std::common_type_t<S1, U2>; 73 accumulate &= test0<S1, U2, Output>(TC.x, TC.y, TC.expect); 74 accumulate &= test0<U2, S1, Output>(TC.x, TC.y, TC.expect); 75 accumulate &= test0<S1, U2, Output>(-TC.x, TC.y, TC.expect); 76 accumulate &= test0<U2, S1, Output>(TC.x, -TC.y, TC.expect); 77 } 78 { // Test with mixed signs 79 using Output = std::common_type_t<S2, U1>; 80 accumulate &= test0<S2, U1, Output>(TC.x, TC.y, TC.expect); 81 accumulate &= test0<U1, S2, Output>(TC.x, TC.y, TC.expect); 82 accumulate &= test0<S2, U1, Output>(-TC.x, TC.y, TC.expect); 83 accumulate &= test0<U1, S2, Output>(TC.x, -TC.y, TC.expect); 84 } 85 } 86 return accumulate; 87 } 88 89 int main() 90 { 91 auto non_cce = std::rand(); // a value that can't possibly be constexpr 92 93 static_assert(do_test<signed char>(), ""); 94 static_assert(do_test<short>(), ""); 95 static_assert(do_test<int>(), ""); 96 static_assert(do_test<long>(), ""); 97 static_assert(do_test<long long>(), ""); 98 99 assert(do_test<signed char>(non_cce)); 100 assert(do_test<short>(non_cce)); 101 assert(do_test<int>(non_cce)); 102 assert(do_test<long>(non_cce)); 103 assert(do_test<long long>(non_cce)); 104 105 static_assert(do_test< int8_t>(), ""); 106 static_assert(do_test<int16_t>(), ""); 107 static_assert(do_test<int32_t>(), ""); 108 static_assert(do_test<int64_t>(), ""); 109 110 assert(do_test< int8_t>(non_cce)); 111 assert(do_test<int16_t>(non_cce)); 112 assert(do_test<int32_t>(non_cce)); 113 assert(do_test<int64_t>(non_cce)); 114 115 static_assert(do_test<signed char, int>(), ""); 116 static_assert(do_test<int, signed char>(), ""); 117 static_assert(do_test<short, int>(), ""); 118 static_assert(do_test<int, short>(), ""); 119 static_assert(do_test<int, long>(), ""); 120 static_assert(do_test<long, int>(), ""); 121 static_assert(do_test<int, long long>(), ""); 122 static_assert(do_test<long long, int>(), ""); 123 124 assert((do_test<signed char, int>(non_cce))); 125 assert((do_test<int, signed char>(non_cce))); 126 assert((do_test<short, int>(non_cce))); 127 assert((do_test<int, short>(non_cce))); 128 assert((do_test<int, long>(non_cce))); 129 assert((do_test<long, int>(non_cce))); 130 assert((do_test<int, long long>(non_cce))); 131 assert((do_test<long long, int>(non_cce))); 132 } 133