1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout synced 2024-11-12 21:09:01 +00:00
Sprout/sprout/string/float_to_string.hpp
2012-04-16 19:49:23 +09:00

243 lines
9.1 KiB
C++

#ifndef SPROUT_STRING_FLOAT_TO_STRING_HPP
#define SPROUT_STRING_FLOAT_TO_STRING_HPP
#include <cstddef>
#include <cstdint>
#include <cmath>
#include <limits>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/string/string.hpp>
#include <sprout/string/make_string.hpp>
#include <sprout/integer/integer_digits.hpp>
#include <sprout/utility/enabler_if.hpp>
#include <sprout/detail/char_conversion.hpp>
namespace sprout {
SPROUT_STATIC_CONSTEXPR std::size_t decimal_places_length = 6;
//
// printed_float_digits
//
template<typename FloatType>
struct printed_float_digits
: public std::integral_constant<
std::size_t,
/*std::numeric_limits<floatFloatType>::max_exponent10 + decimal_places_length + 3*/
sprout::integer_digits<std::intmax_t>::value + decimal_places_length + 3
>
{};
namespace detail {
template<typename FloatType>
inline SPROUT_CONSTEXPR unsigned float_extract_rounded_impl(FloatType val) {
return static_cast<unsigned>(val * 1000000)
+ (static_cast<unsigned>(val * 10000000) % 10 >= 5 ? 1 : 0)
;
}
template<typename FloatType>
inline SPROUT_CONSTEXPR unsigned float_extract_rounded(FloatType val) {
using std::floor;
return sprout::detail::float_extract_rounded_impl(val - floor(val));
}
template<
typename Elem,
typename FloatType,
typename... Args,
typename sprout::enabler_if<(sizeof...(Args) == sprout::printed_float_digits<FloatType>::value - 1)>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string_impl_1(FloatType val, bool negative, Args... args) {
return negative ? sprout::make_string_as<Elem>(static_cast<Elem>('-'), args...)
: sprout::make_string_as<Elem>(args...)
;
}
template<
typename Elem,
typename FloatType,
typename... Args,
typename sprout::enabler_if<(sizeof...(Args) < sprout::printed_float_digits<FloatType>::value - 1)>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string_impl_1(FloatType val, bool negative, Args... args) {
return !(val < 1) ? sprout::detail::float_to_string_impl_1<Elem>(
val / 10,
negative,
sprout::detail::int_to_char<Elem>(static_cast<std::uintmax_t>(val) % 10),
args...
)
: negative ? sprout::make_string_as<Elem>(static_cast<Elem>('-'), args...)
: sprout::make_string_as<Elem>(args...)
;
}
template<
typename Elem,
typename FloatType,
typename... Args,
typename sprout::enabler_if<(sizeof...(Args) == sprout::printed_float_digits<FloatType>::value - 3)>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string_impl(FloatType val, bool negative, unsigned temp, std::size_t decimal_digits, Args... args) {
return negative ? sprout::make_string_as<Elem>(static_cast<Elem>('-'), static_cast<Elem>('0'), static_cast<Elem>('.'), args...)
: sprout::make_string_as<Elem>(static_cast<Elem>('0'), static_cast<Elem>('.'), args...)
;
}
template<
typename Elem,
typename FloatType,
typename... Args,
typename sprout::enabler_if<(sizeof...(Args) < sprout::printed_float_digits<FloatType>::value - 3)>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string_impl(FloatType val, bool negative, unsigned temp, std::size_t decimal_digits, Args... args) {
return decimal_digits ? sprout::detail::float_to_string_impl<Elem>(
val,
negative,
temp / 10,
decimal_digits - 1,
sprout::detail::int_to_char<Elem>(temp % 10),
args...
)
: !(val < 1) ? sprout::detail::float_to_string_impl_1<Elem>(
val,
negative,
static_cast<Elem>('.'),
args...
)
: negative ? sprout::make_string_as<Elem>(static_cast<Elem>('-'), static_cast<Elem>('0'), static_cast<Elem>('.'), args...)
: sprout::make_string_as<Elem>(static_cast<Elem>('0'), static_cast<Elem>('.'), args...)
;
}
template<
typename Elem,
typename FloatType
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string(FloatType val) {
using std::floor;
return val < 0 ? sprout::detail::float_to_string_impl<Elem>(
-val,
true,
sprout::detail::float_extract_rounded(-val),
decimal_places_length
)
: sprout::detail::float_to_string_impl<Elem>(
val,
false,
sprout::detail::float_extract_rounded(val),
decimal_places_length
)
;
}
} // namespace detail
//
// float_to_string
//
template<
typename Elem,
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string(FloatType val) {
return sprout::detail::float_to_string<Elem>(val);
}
//
// to_string_of
//
template<typename Elem, typename FloatType, typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
to_string_of(FloatType val) {
return sprout::float_to_string<Elem>(val);
}
//
// to_string
//
// inline SPROUT_CONSTEXPR sprout::basic_string<char, sprout::printed_float_digits<float>::value>
// to_string(float val) {
// return sprout::to_string_of<char>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char, sprout::printed_float_digits<double>::value>
// to_string(double val) {
// return sprout::to_string_of<char>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char, sprout::printed_float_digits<long double>::value>
// to_string(long double val) {
// return sprout::to_string_of<char>(val);
// }
template<typename FloatType, typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR sprout::basic_string<char, sprout::printed_float_digits<FloatType>::value>
to_string(FloatType val) {
return sprout::to_string_of<char>(val);
}
//
// to_wstring
//
// inline SPROUT_CONSTEXPR sprout::basic_string<wchar_t, sprout::printed_float_digits<float>::value>
// to_wstring(float val) {
// return sprout::to_string_of<wchar_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<wchar_t, sprout::printed_float_digits<double>::value>
// to_wstring(double val) {
// return sprout::to_string_of<wchar_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<wchar_t, sprout::printed_float_digits<long double>::value>
// to_wstring(long double val) {
// return sprout::to_string_of<wchar_t>(val);
// }
template<typename FloatType, typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR sprout::basic_string<wchar_t, sprout::printed_float_digits<FloatType>::value>
to_wstring(FloatType val) {
return sprout::to_string_of<wchar_t>(val);
}
//
// to_u16string
//
// inline SPROUT_CONSTEXPR sprout::basic_string<char16_t, sprout::printed_float_digits<float>::value>
// to_u16string(float val) {
// return sprout::to_string_of<char16_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char16_t, sprout::printed_float_digits<double>::value>
// to_u16string(double val) {
// return sprout::to_string_of<char16_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char16_t, sprout::printed_float_digits<long double>::value>
// to_u16string(long double val) {
// return sprout::to_string_of<char16_t>(val);
// }
template<typename FloatType, typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR sprout::basic_string<char16_t, sprout::printed_float_digits<FloatType>::value>
to_u16string(FloatType val) {
return sprout::to_string_of<char16_t>(val);
}
//
// to_u32string
//
// inline SPROUT_CONSTEXPR sprout::basic_string<char32_t, sprout::printed_float_digits<float>::value>
// to_u32string(float val) {
// return sprout::to_string_of<char32_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char32_t, sprout::printed_float_digits<double>::value>
// to_u32string(double val) {
// return sprout::to_string_of<char32_t>(val);
// }
// inline SPROUT_CONSTEXPR sprout::basic_string<char32_t, sprout::printed_float_digits<long double>::value>
// to_u32string(long double val) {
// return sprout::to_string_of<char32_t>(val);
// }
template<typename FloatType, typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR sprout::basic_string<char32_t, sprout::printed_float_digits<FloatType>::value>
to_u32string(FloatType val) {
return sprout::to_string_of<char32_t>(val);
}
} // namespace sprout
#endif // #ifndef SPROUT_STRING_FLOAT_TO_STRING_HPP