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Sprout/sprout/string/float_to_string.hpp
bolero-MURAKAMI b9440c0e9c support for VC++2015
2015-12-09 19:54:35 +09:00

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/*=============================================================================
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_STRING_FLOAT_TO_STRING_HPP
#define SPROUT_STRING_FLOAT_TO_STRING_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/limits.hpp>
#include <sprout/index_tuple/metafunction.hpp>
#include <sprout/string/string.hpp>
#include <sprout/type_traits/integral_constant.hpp>
#include <sprout/type_traits/enabler_if.hpp>
#include <sprout/math/isinf.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/math/signbit.hpp>
#include <sprout/math/floor.hpp>
#include <sprout/tpp/algorithm/max_element.hpp>
#include <sprout/detail/char_literal.hpp>
#include <sprout/detail/char_conversion.hpp>
#include <sprout/detail/math/int.hpp>
#include <sprout/detail/math/float.hpp>
#include HDR_ALGORITHM_MIN_MAX_SSCRISK_CEL_OR_SPROUT
namespace sprout {
namespace detail {
SPROUT_STATIC_CONSTEXPR std::size_t decimal_places_length = 6;
} // namespace detail
//
// printed_float_digits
//
template<typename FloatType>
struct printed_float_digits
: public sprout::integral_constant<
std::size_t,
sprout::numeric_limits<FloatType>::max_exponent10 + sprout::detail::decimal_places_length + 2
>
{};
namespace detail {
template<typename Elem, typename FloatType, sprout::index_t... Indexes>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string_impl(FloatType val, bool negative, int digits, int v, sprout::index_tuple<Indexes...>) {
typedef sprout::detail::string_construct_access<Elem, sprout::printed_float_digits<FloatType>::value> access_type;
return negative
? access_type::raw_construct(
static_cast<std::size_t>(digits + 2 + sprout::detail::decimal_places_length),
SPROUT_CHAR_LITERAL('-', Elem),
(Indexes < digits ? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, digits - 1 - Indexes))
: Indexes == digits ? SPROUT_CHAR_LITERAL('.', Elem)
: Indexes < digits + 1 + sprout::detail::decimal_places_length
? sprout::detail::int_to_char<Elem>(sprout::detail::int_digit_at(v, digits + sprout::detail::decimal_places_length - Indexes))
: Elem()
)...
)
: access_type::raw_construct(
static_cast<std::size_t>(digits + 1 + sprout::detail::decimal_places_length),
(Indexes < digits ? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, digits - 1 - Indexes))
: Indexes == digits ? SPROUT_CHAR_LITERAL('.', Elem)
: Indexes < digits + 1 + sprout::detail::decimal_places_length
? sprout::detail::int_to_char<Elem>(sprout::detail::int_digit_at(v, digits + sprout::detail::decimal_places_length - Indexes))
: Elem()
)...
)
;
}
template<typename Elem, typename FloatType>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_digits<FloatType>::value>
float_to_string(FloatType val, bool negative, int digits) {
return sprout::detail::float_to_string_impl<Elem>(
val, negative, digits, static_cast<int>((val - sprout::math::floor(val)) * sprout::detail::int_pow<int>(sprout::detail::decimal_places_length)),
sprout::make_index_tuple<sprout::printed_float_digits<FloatType>::value - 1>::make()
);
}
} // 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) {
typedef sprout::detail::string_construct_access<Elem, sprout::printed_float_digits<FloatType>::value> access_type;
return sprout::math::isinf(val) ? sprout::math::signbit(val)
? access_type::raw_construct(4, SPROUT_CHAR_LITERAL('-', Elem), SPROUT_CHAR_LITERAL('i', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('f', Elem))
: access_type::raw_construct(3, SPROUT_CHAR_LITERAL('i', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('f', Elem))
: sprout::math::isnan(val) ? sprout::math::signbit(val)
? access_type::raw_construct(4, SPROUT_CHAR_LITERAL('-', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('a', Elem), SPROUT_CHAR_LITERAL('n', Elem))
: access_type::raw_construct(3, SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('a', Elem), SPROUT_CHAR_LITERAL('n', Elem))
: sprout::detail::float_to_string<Elem>(
sprout::detail::float_round_at(val < 0 ? -val : val, sprout::detail::decimal_places_length),
sprout::math::signbit(val),
sprout::detail::float_digits_checked(val)
)
;
}
namespace detail {
template<typename FloatType>
struct printed_float_exponent10_digits
: public sprout::integral_constant<
std::size_t,
sprout::tpp::max_element_c<int, sprout::detail::int_digits_mf<int, sprout::numeric_limits<FloatType>::max_exponent10>::value, 2>::value
>
{};
} // namespace detail
//
// printed_float_exp_digits
//
template<typename FloatType>
struct printed_float_exp_digits
: public sprout::integral_constant<
std::size_t,
5 + sprout::detail::decimal_places_length + sprout::detail::printed_float_exponent10_digits<FloatType>::value
>
{};
namespace detail {
template<typename Elem, typename FloatType, sprout::index_t... Indexes>
inline SPROUT_CONSTEXPR sprout::basic_string<Elem, sprout::printed_float_exp_digits<FloatType>::value>
float_to_string_exp(FloatType val, bool negative, int exponent10, int e10_digits, sprout::index_tuple<Indexes...>) {
typedef sprout::detail::string_construct_access<Elem, sprout::printed_float_exp_digits<FloatType>::value> access_type;
return negative
? access_type::raw_construct(
static_cast<std::size_t>(5 + sprout::detail::decimal_places_length + e10_digits),
SPROUT_CHAR_LITERAL('-', Elem),
(Indexes == 0 ? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, 0))
: Indexes == 1 ? SPROUT_CHAR_LITERAL('.', Elem)
: Indexes < 2 + sprout::detail::decimal_places_length
? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, 1 - Indexes))
: Indexes == 2 + sprout::detail::decimal_places_length ? SPROUT_CHAR_LITERAL('e', Elem)
: Indexes == 3 + sprout::detail::decimal_places_length ? (exponent10 < 0 ? SPROUT_CHAR_LITERAL('-', Elem) : SPROUT_CHAR_LITERAL('+', Elem))
: Indexes < 4 + sprout::detail::decimal_places_length + e10_digits
? sprout::detail::int_to_char<Elem>(sprout::detail::int_digit_at(exponent10, 3 + sprout::detail::decimal_places_length + e10_digits - Indexes))
: Elem()
)...
)
: access_type::raw_construct(
static_cast<std::size_t>(4 + sprout::detail::decimal_places_length + e10_digits),
(Indexes == 0 ? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, 0))
: Indexes == 1 ? SPROUT_CHAR_LITERAL('.', Elem)
: Indexes < 2 + sprout::detail::decimal_places_length
? sprout::detail::int_to_char<Elem>(sprout::detail::float_digit_at(val, 1 - Indexes))
: Indexes == 2 + sprout::detail::decimal_places_length ? SPROUT_CHAR_LITERAL('e', Elem)
: Indexes == 3 + sprout::detail::decimal_places_length ? (exponent10 < 0 ? SPROUT_CHAR_LITERAL('-', Elem) : SPROUT_CHAR_LITERAL('+', Elem))
: Indexes < 4 + sprout::detail::decimal_places_length + e10_digits
? sprout::detail::int_to_char<Elem>(sprout::detail::int_digit_at(exponent10, 3 + sprout::detail::decimal_places_length + e10_digits - Indexes))
: Elem()
)...
)
;
}
} // namespace detail
//
// float_to_string_exp
//
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_exp_digits<FloatType>::value>
float_to_string_exp(FloatType val) {
typedef sprout::detail::string_construct_access<Elem, sprout::printed_float_exp_digits<FloatType>::value> access_type;
return sprout::math::isinf(val) ? sprout::math::signbit(val)
? access_type::raw_construct(4, SPROUT_CHAR_LITERAL('-', Elem), SPROUT_CHAR_LITERAL('i', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('f', Elem))
: access_type::raw_construct(3, SPROUT_CHAR_LITERAL('i', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('f', Elem))
: sprout::math::isnan(val) ? sprout::math::signbit(val)
? access_type::raw_construct(4, SPROUT_CHAR_LITERAL('-', Elem), SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('a', Elem), SPROUT_CHAR_LITERAL('n', Elem))
: access_type::raw_construct(3, SPROUT_CHAR_LITERAL('n', Elem), SPROUT_CHAR_LITERAL('a', Elem), SPROUT_CHAR_LITERAL('n', Elem))
: sprout::detail::float_to_string_exp<Elem>(
sprout::detail::float_round_at(
(val < 0 ? -val : val) / sprout::detail::float_pow10<FloatType>(sprout::detail::float_exponent10(val)),
sprout::detail::decimal_places_length
),
sprout::math::signbit(val),
sprout::detail::float_exponent10(val),
NS_SSCRISK_CEL_OR_SPROUT::max(sprout::detail::int_digits(sprout::detail::float_exponent10(val)), 2),
sprout::make_index_tuple<sprout::printed_float_exp_digits<FloatType>::value - 1>::make()
)
;
}
//
// 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
//
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
//
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
//
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
//
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
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