mirror/Sprout
1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout.git synced 2025-07-14 15:04:09 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

support C++14 constexpr: random distributions

Browse source
This commit is contained in:
bolero-MURAKAMI 2013-11-05 23:46:23 +09:00
parent 230630b45b
commit 3c4a465d35
9 changed files with 468 additions and 60 deletions
Download patch file Download diff file Expand all files Collapse all files

58
sprout/random/uniform_smallint.hpp
View file

@ -89,6 +89,39 @@ namespace sprout {
IntType min_;
IntType max_;
private:
template<typename Engine>
SPROUT_CXX14_CONSTEXPR result_type generate(
Engine& eng,
std::true_type
) const
{
typedef typename Engine::result_type base_result;
typedef typename std::make_unsigned<base_result>::type base_unsigned;
typedef typename std::make_unsigned<result_type>::type range_type;
range_type range = sprout::random::detail::subtract<result_type>()(max_, min_);
base_unsigned base_range = sprout::random::detail::subtract<result_type>()(eng.max(), eng.min());
base_unsigned val = sprout::random::detail::subtract<base_result>()(static_cast<base_result>(eng()), eng.min());
return range >= base_range
? sprout::random::detail::add<range_type, result_type>()(static_cast<range_type>(val), min_)
: sprout::random::detail::add<range_type, result_type>()(static_cast<range_type>(val % (static_cast<base_result>(range) + 1)), min_)
;
}
template<class Engine>
SPROUT_CXX14_CONSTEXPR result_type generate(
Engine& eng,
std::false_type
) const
{
typedef typename Engine::result_type base_result;
typedef typename std::make_unsigned<result_type>::type range_type;
range_type range = sprout::random::detail::subtract<result_type>()(max_, min_);
base_result val = sprout::random::uniform_01<base_result>()(eng);
range_type offset = static_cast<range_type>(val * (static_cast<base_result>(range) + 1));
return offset > range
? max_
: sprout::random::detail::add<range_type, result_type>()(offset, min_)
;
}
template<typename Engine, typename EngineResult, typename RangeType, typename BaseUnsigned>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> generate_true_2(
Engine const&,
@ -176,8 +209,8 @@ namespace sprout {
return generate_false_2(
eng,
rnd,
RangeType(sprout::random::detail::subtract<result_type>()(max_, min_)),
RangeType(static_cast<RangeType>(rnd.result() * (static_cast<base_result>(range) + 1)))
static_cast<RangeType>(sprout::random::detail::subtract<result_type>()(max_, min_)),
static_cast<RangeType>(rnd.result() * (static_cast<base_result>(range) + 1))
);
}
template<class Engine>
@ -191,11 +224,11 @@ namespace sprout {
return generate_false_1(
eng,
sprout::random::uniform_01<base_result>()(eng),
range_type(sprout::random::detail::subtract<result_type>()(max_, min_))
static_cast<range_type>(sprout::random::detail::subtract<result_type>()(max_, min_))
);
}
public:
SPROUT_CONSTEXPR uniform_smallint()
SPROUT_CONSTEXPR uniform_smallint() SPROUT_NOEXCEPT
: min_(0)
, max_(9)
{}
@ -203,7 +236,7 @@ namespace sprout {
: min_((SPROUT_ASSERT(min_arg <= max_arg), min_arg))
, max_(max_arg)
{}
explicit SPROUT_CONSTEXPR uniform_smallint(param_type const& parm)
explicit SPROUT_CONSTEXPR uniform_smallint(param_type const& parm) SPROUT_NOEXCEPT
: min_(parm.a())
, max_(parm.b())
{}
@ -227,10 +260,25 @@ namespace sprout {
max_ = parm.b();
}
template<typename Engine>
SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng) const {
typedef typename Engine::result_type base_result;
return generate(eng, typename std::is_integral<base_result>::type());
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> const operator()(Engine const& eng) const {
typedef typename Engine::result_type base_result;
return generate(eng, typename std::is_integral<base_result>::type());
}
template<typename Engine>
SPROUT_CXX14_CONSTEXPR result_type operator()(Engine& eng, param_type const& parm) const {
typedef typename Engine::result_type base_result;
return uniform_smallint(parm)(eng);
}
template<typename Engine>
SPROUT_CONSTEXPR sprout::random::random_result<Engine, uniform_smallint> const operator()(Engine const& eng, param_type const& parm) const {
typedef typename Engine::result_type base_result;
return uniform_smallint(parm)(eng);
}
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,