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 // <algorithm>
11 
12 // __half_positive divides an integer number by 2 as unsigned number for known types.
13 // It can be an important optimization for lower bound, for example.
14 
15 #include <algorithm>
16 #include <cassert>
17 #include <limits>
18 #include <type_traits>
19 
20 #include "test_macros.h"
21 #include "user_defined_integral.hpp"
22 
23 namespace {
24 
25 template <class IntType, class UnderlyingType = IntType>
test(IntType max_v=IntType (std::numeric_limits<UnderlyingType>::max ()))26 TEST_CONSTEXPR bool test(IntType max_v = IntType(std::numeric_limits<UnderlyingType>::max())) {
27     return std::__half_positive(max_v) == max_v / 2;
28 }
29 
30 }  // namespace
31 
main()32 int main()
33 {
34     {
35         assert(test<char>());
36         assert(test<int>());
37         assert(test<long>());
38         assert((test<UserDefinedIntegral<int>, int>()));
39         assert(test<size_t>());
40 #if !defined(_LIBCPP_HAS_NO_INT128)
41         assert(test<__int128_t>());
42 #endif  // !defined(_LIBCPP_HAS_NO_INT128)
43     }
44 
45 #if TEST_STD_VER >= 11
46     {
47         static_assert(test<char>(), "");
48         static_assert(test<int>(), "");
49         static_assert(test<long>(), "");
50         static_assert(test<size_t>(), "");
51 #if !defined(_LIBCPP_HAS_NO_INT128)
52         static_assert(test<__int128_t>(), "");
53 #endif  // !defined(_LIBCPP_HAS_NO_INT128)
54     }
55 #endif // TEST_STD_VER >= 11
56 }
57