1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout synced 2024-11-12 21:09:01 +00:00
Sprout/sprout/stateful/rand.hpp
bolero-MURAKAMI 559db060ab add inline
2015-05-21 01:07:29 +09:00

218 lines
7.1 KiB
C++

/*=============================================================================
Copyright (c) 2011-2015 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_STATEFUL_RAND_HPP
#define SPROUT_STATEFUL_RAND_HPP
#include <cstdlib>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/utility/as_const.hpp>
#include <sprout/random/default_random_engine.hpp>
#include <sprout/random/random_result.hpp>
#include <sprout/random/unique_seed.hpp>
#include <sprout/type_traits/integral_constant.hpp>
#include <sprout/workaround/detail/uniform_int_distribution.hpp>
namespace sprout {
#ifndef SPROUT_CONFIG_DISABLE_CONSTEXPR
namespace detail {
typedef sprout::random::default_random_engine rand_generator_type;
typedef SPROUT_WORKAROUND_DETAIL_UNIFORM_INT_DISTRIBUTION<int> rand_distribution_type;
typedef sprout::random::random_result<
sprout::detail::rand_generator_type,
sprout::detail::rand_distribution_type
> rand_result_type;
SPROUT_STATIC_CONSTEXPR std::size_t rand_default_seed = SPROUT_UNIQUE_SEED;
} // namespace detail
namespace rand_detail {
#if defined(__GNUC__) && !defined(__clang__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wnon-template-friend"
#endif
#if defined(__clang__)
# pragma clang diagnostic push
# pragma clang diagnostic ignored "-Wundefined-inline"
#endif
template<int N>
struct tag {
friend SPROUT_CONSTEXPR int adl_counter(sprout::rand_detail::tag<N>);
friend SPROUT_CONSTEXPR bool adl_is_srand(sprout::rand_detail::tag<N>);
friend SPROUT_CONSTEXPR unsigned adl_seed(sprout::rand_detail::tag<N>);
};
#if defined(__clang__)
# pragma clang diagnostic pop
#endif
#if defined(__GNUC__) && !defined(__clang__)
# pragma GCC diagnostic pop
#endif
template<int N, bool IsSrand = false, unsigned Seed = 0>
struct state {
friend SPROUT_CONSTEXPR int adl_counter(sprout::rand_detail::tag<N>) {
return N;
}
friend SPROUT_CONSTEXPR bool adl_is_srand(sprout::rand_detail::tag<N>) {
return IsSrand;
}
friend SPROUT_CONSTEXPR unsigned adl_seed(sprout::rand_detail::tag<N>) {
return Seed;
}
// generate a next random number
SPROUT_STATIC_CONSTEXPR sprout::detail::rand_result_type result
SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER((
!IsSrand
? sprout::rand_detail::state<
N - 1,
adl_is_srand(sprout::rand_detail::tag<N - 1>()),
adl_seed(sprout::rand_detail::tag<N - 1>())
>::result()
: sprout::detail::rand_result_type(
Seed,
sprout::detail::rand_generator_type(Seed),
sprout::detail::rand_distribution_type(0, RAND_MAX)
)
))
;
SPROUT_STATIC_CONSTEXPR int value = result;
};
template<int N, bool IsSrand, unsigned Seed>
SPROUT_CONSTEXPR_OR_CONST sprout::detail::rand_result_type sprout::rand_detail::state<N, IsSrand, Seed>::result
SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER((
!IsSrand
? sprout::rand_detail::state<
N - 1,
adl_is_srand(sprout::rand_detail::tag<N - 1>()),
adl_seed(sprout::rand_detail::tag<N - 1>())
>::result()
: sprout::detail::rand_result_type(
0,
sprout::detail::rand_generator_type(Seed),
sprout::detail::rand_distribution_type(0, RAND_MAX)
)
))
;
template<int N, bool IsSrand, unsigned Seed>
SPROUT_CONSTEXPR_OR_CONST int sprout::rand_detail::state<N, IsSrand, Seed>::value;
template<bool IsSrand, unsigned Seed>
struct state<0, IsSrand, Seed> {
friend SPROUT_CONSTEXPR int adl_counter(sprout::rand_detail::tag<0>) {
return 0;
}
friend SPROUT_CONSTEXPR bool adl_is_srand(sprout::rand_detail::tag<0>) {
return IsSrand;
}
friend SPROUT_CONSTEXPR unsigned adl_seed(sprout::rand_detail::tag<0>) {
return Seed;
}
// generate a first random number between [0, RAND_MAX]
SPROUT_STATIC_CONSTEXPR sprout::detail::rand_result_type result
SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER((
!IsSrand
? sprout::detail::rand_distribution_type(0, RAND_MAX)
(sprout::as_const(sprout::detail::rand_generator_type(!IsSrand ? sprout::detail::rand_default_seed : Seed)))
: sprout::detail::rand_result_type(
Seed,
sprout::detail::rand_generator_type(Seed),
sprout::detail::rand_distribution_type(0, RAND_MAX)
)
))
;
static SPROUT_CONSTEXPR int value = result;
};
template<bool IsSrand, unsigned Seed>
SPROUT_CONSTEXPR_OR_CONST sprout::detail::rand_result_type sprout::rand_detail::state<0, IsSrand, Seed>::result
SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(
!IsSrand
? sprout::detail::rand_distribution_type(0, RAND_MAX)
(sprout::as_const(sprout::detail::rand_generator_type(!IsSrand ? sprout::detail::rand_default_seed : Seed)))
: sprout::detail::rand_result_type(
Seed,
sprout::detail::rand_generator_type(Seed),
sprout::detail::rand_distribution_type(0, RAND_MAX)
)
)
;
template<bool IsSrand, unsigned Seed>
SPROUT_CONSTEXPR_OR_CONST int sprout::rand_detail::state<0, IsSrand, Seed>::value;
template<int N, int = adl_counter(sprout::rand_detail::tag<N>())>
inline SPROUT_CONSTEXPR bool check(int, sprout::rand_detail::tag<N>) {
return true;
}
template<int N>
inline SPROUT_CONSTEXPR bool check(long, sprout::rand_detail::tag<N>) {
return false;
}
template<int N>
inline SPROUT_CONSTEXPR bool check(bool R = sprout::rand_detail::check(0, sprout::rand_detail::tag<N>())) {
return R;
}
template<int N>
inline SPROUT_CONSTEXPR int counter(sprout::false_type, sprout::rand_detail::tag<N>) {
return 0;
}
template<int N>
inline SPROUT_CONSTEXPR int counter(
sprout::true_type, sprout::rand_detail::tag<N>,
int R = !sprout::rand_detail::check<N>() ? N
: counter(sprout::bool_constant<sprout::rand_detail::check<N>()>(), sprout::rand_detail::tag<N + 1>())
)
{
return R;
}
template<int N = 0>
inline SPROUT_CONSTEXPR int counter(int R = sprout::rand_detail::counter(sprout::true_type(), sprout::rand_detail::tag<N>())) {
return R;
}
} // namespace rand_detail
//
// rand
//
template<
int N = 1,
int R = sprout::rand_detail::state<
sprout::rand_detail::counter() + N - 1
>::value
>
inline SPROUT_CONSTEXPR int rand() {
return R;
}
//
// srand
// srand_return
//
template<
unsigned Seed,
int N = 1,
int = sprout::rand_detail::state<
sprout::rand_detail::counter() + N - 1,
true, Seed
>::value
>
SPROUT_CXX14_CONSTEXPR void srand() {}
template<
unsigned Seed,
int N = 1,
int R = sprout::rand_detail::state<
sprout::rand_detail::counter() + N - 1,
true, Seed
>::value
>
inline SPROUT_CONSTEXPR unsigned srand_return() {
return R;
}
#endif
} // namespace sprout
#endif // #ifndef SPROUT_STATEFUL_RAND_HPP