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Sprout/sprout/random/uniform_01.hpp
bolero-MURAKAMI 4a345e8259 random 更新
2011-09-29 22:46:32 +09:00

91 lines
2.4 KiB
C++

#ifndef SPROUT_RANDOM_UNIFORM_01_HPP
#define SPROUT_RANDOM_UNIFORM_01_HPP
#include <iosfwd>
#include <limits>
#include <sprout/config.hpp>
#include <sprout/random/random_result.hpp>
namespace sprout {
namespace random {
//
// uniform_01
//
template<typename RealType = double>
class uniform_01 {
public:
typedef RealType input_type;
typedef RealType result_type;
private:
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> generate_1(
Engine const& eng,
sprout::random::random_result<Engine> const& rnd,
result_type result
) const
{
return result < result_type(1)
? sprout::random::random_result<Engine, uniform_01>(result, rnd.engine(), *this)
: operator()(rnd.engine())
;
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> generate(
Engine const& eng,
sprout::random::random_result<Engine> const& rnd
) const
{
typedef typename Engine::result_type base_result;
return generate_1(
eng,
rnd,
result_type(rnd.result() - eng.min()) * (
result_type(1) / (
result_type(eng.max() - eng.min()) + result_type(
std::numeric_limits<base_result>::is_integer ? 1 : 0
)
)
)
);
}
public:
SPROUT_CONSTEXPR result_type min() const {
return result_type(0);
}
SPROUT_CONSTEXPR result_type max() const {
return result_type(1);
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_01> operator()(Engine const& eng) const {
return generate(eng, eng());
}
template<typename Elem, typename Traits>
friend std::basic_ostream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,
uniform_01 const& rhs
)
{
return lhs;
}
template<typename Elem, typename Traits>
friend std::basic_ostream<Elem, Traits>& operator<<(
std::basic_ostream<Elem, Traits>& lhs,
uniform_01 const& rhs
)
{
return lhs;
}
SPROUT_CONSTEXPR friend bool operator==(uniform_01 const& lhs, uniform_01 const& rhs) {
return true;
}
SPROUT_CONSTEXPR friend bool operator!=(uniform_01 const& lhs, uniform_01 const& rhs) {
return !(lhs == rhs);
}
};
} // namespace random
using sprout::random::uniform_01;
} // namespace sprout
#endif // #ifndef SPROUT_RANDOM_UNIFORM_01_HPP