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 #ifndef _LIBCPP___RANDOM_IS_VALID_H 10 #define _LIBCPP___RANDOM_IS_VALID_H 11 12 #include <__config> 13 #include <__type_traits/enable_if.h> 14 #include <__type_traits/integral_constant.h> 15 #include <__type_traits/is_same.h> 16 #include <__type_traits/is_unsigned.h> 17 #include <__utility/declval.h> 18 #include <cstdint> 19 20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 21 # pragma GCC system_header 22 #endif 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 // [rand.req.genl]/1.5: 27 // The effect of instantiating a template that has a template type parameter 28 // named IntType is undefined unless the corresponding template argument is 29 // cv-unqualified and is one of short, int, long, long long, unsigned short, 30 // unsigned int, unsigned long, or unsigned long long. 31 32 template<class> struct __libcpp_random_is_valid_inttype : false_type {}; 33 template<> struct __libcpp_random_is_valid_inttype<int8_t> : true_type {}; // extension 34 template<> struct __libcpp_random_is_valid_inttype<short> : true_type {}; 35 template<> struct __libcpp_random_is_valid_inttype<int> : true_type {}; 36 template<> struct __libcpp_random_is_valid_inttype<long> : true_type {}; 37 template<> struct __libcpp_random_is_valid_inttype<long long> : true_type {}; 38 template<> struct __libcpp_random_is_valid_inttype<uint8_t> : true_type {}; // extension 39 template<> struct __libcpp_random_is_valid_inttype<unsigned short> : true_type {}; 40 template<> struct __libcpp_random_is_valid_inttype<unsigned int> : true_type {}; 41 template<> struct __libcpp_random_is_valid_inttype<unsigned long> : true_type {}; 42 template<> struct __libcpp_random_is_valid_inttype<unsigned long long> : true_type {}; 43 44 #ifndef _LIBCPP_HAS_NO_INT128 45 template<> struct __libcpp_random_is_valid_inttype<__int128_t> : true_type {}; // extension 46 template<> struct __libcpp_random_is_valid_inttype<__uint128_t> : true_type {}; // extension 47 #endif // _LIBCPP_HAS_NO_INT128 48 49 // [rand.req.urng]/3: 50 // A class G meets the uniform random bit generator requirements if G models 51 // uniform_random_bit_generator, invoke_result_t<G&> is an unsigned integer type, 52 // and G provides a nested typedef-name result_type that denotes the same type 53 // as invoke_result_t<G&>. 54 // (In particular, reject URNGs with signed result_types; our distributions cannot 55 // handle such generator types.) 56 57 template<class, class = void> struct __libcpp_random_is_valid_urng : false_type {}; 58 template<class _Gp> struct __libcpp_random_is_valid_urng<_Gp, __enable_if_t< 59 is_unsigned<typename _Gp::result_type>::value && 60 _IsSame<decltype(std::declval<_Gp&>()()), typename _Gp::result_type>::value 61 > > : true_type {}; 62 63 _LIBCPP_END_NAMESPACE_STD 64 65 #endif // _LIBCPP___RANDOM_IS_VALID_H 66