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Diffstat (limited to 'boost/lexical_cast/detail/converter_lexical.hpp')
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diff --git a/boost/lexical_cast/detail/converter_lexical.hpp b/boost/lexical_cast/detail/converter_lexical.hpp new file mode 100644 index 0000000000..ee9f5f132e --- /dev/null +++ b/boost/lexical_cast/detail/converter_lexical.hpp @@ -0,0 +1,520 @@ +// Copyright Kevlin Henney, 2000-2005. +// Copyright Alexander Nasonov, 2006-2010. +// Copyright Antony Polukhin, 2011-2014. +// +// 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) +// +// what: lexical_cast custom keyword cast +// who: contributed by Kevlin Henney, +// enhanced with contributions from Terje Slettebo, +// with additional fixes and suggestions from Gennaro Prota, +// Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov, +// Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann, +// Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters +// when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014 + +#ifndef BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_HPP +#define BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_HPP + +#include <boost/config.hpp> +#ifdef BOOST_HAS_PRAGMA_ONCE +# pragma once +#endif + +#if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING) +#define BOOST_LCAST_NO_WCHAR_T +#endif + +#include <cstddef> +#include <string> +#include <boost/limits.hpp> +#include <boost/mpl/if.hpp> +#include <boost/type_traits/ice.hpp> +#include <boost/type_traits/is_integral.hpp> +#include <boost/type_traits/is_float.hpp> +#include <boost/type_traits/has_left_shift.hpp> +#include <boost/type_traits/has_right_shift.hpp> +#include <boost/static_assert.hpp> +#include <boost/detail/lcast_precision.hpp> + +#include <boost/lexical_cast/detail/widest_char.hpp> +#include <boost/lexical_cast/detail/is_character.hpp> + +#ifndef BOOST_NO_CXX11_HDR_ARRAY +#include <array> +#endif + +#include <boost/array.hpp> +#include <boost/range/iterator_range_core.hpp> +#include <boost/container/container_fwd.hpp> + +#include <boost/lexical_cast/detail/converter_lexical_streams.hpp> + +namespace boost { + + namespace detail // normalize_single_byte_char<Char> + { + // Converts signed/unsigned char to char + template < class Char > + struct normalize_single_byte_char + { + typedef Char type; + }; + + template <> + struct normalize_single_byte_char< signed char > + { + typedef char type; + }; + + template <> + struct normalize_single_byte_char< unsigned char > + { + typedef char type; + }; + } + + namespace detail // deduce_character_type_later<T> + { + // Helper type, meaning that stram character for T must be deduced + // at Stage 2 (See deduce_source_char<T> and deduce_target_char<T>) + template < class T > struct deduce_character_type_later {}; + } + + namespace detail // stream_char_common<T> + { + // Selectors to choose stream character type (common for Source and Target) + // Returns one of char, wchar_t, char16_t, char32_t or deduce_character_type_later<T> types + // Executed on Stage 1 (See deduce_source_char<T> and deduce_target_char<T>) + template < typename Type > + struct stream_char_common: public boost::mpl::if_c< + boost::detail::is_character< Type >::value, + Type, + boost::detail::deduce_character_type_later< Type > + > {}; + + template < typename Char > + struct stream_char_common< Char* >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< Char* > + > {}; + + template < typename Char > + struct stream_char_common< const Char* >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< const Char* > + > {}; + + template < typename Char > + struct stream_char_common< boost::iterator_range< Char* > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< boost::iterator_range< Char* > > + > {}; + + template < typename Char > + struct stream_char_common< boost::iterator_range< const Char* > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< boost::iterator_range< const Char* > > + > {}; + + template < class Char, class Traits, class Alloc > + struct stream_char_common< std::basic_string< Char, Traits, Alloc > > + { + typedef Char type; + }; + + template < class Char, class Traits, class Alloc > + struct stream_char_common< boost::container::basic_string< Char, Traits, Alloc > > + { + typedef Char type; + }; + + template < typename Char, std::size_t N > + struct stream_char_common< boost::array< Char, N > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< boost::array< Char, N > > + > {}; + + template < typename Char, std::size_t N > + struct stream_char_common< boost::array< const Char, N > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< boost::array< const Char, N > > + > {}; + +#ifndef BOOST_NO_CXX11_HDR_ARRAY + template < typename Char, std::size_t N > + struct stream_char_common< std::array<Char, N > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< std::array< Char, N > > + > {}; + + template < typename Char, std::size_t N > + struct stream_char_common< std::array< const Char, N > >: public boost::mpl::if_c< + boost::detail::is_character< Char >::value, + Char, + boost::detail::deduce_character_type_later< std::array< const Char, N > > + > {}; +#endif + +#ifdef BOOST_HAS_INT128 + template <> struct stream_char_common< boost::int128_type >: public boost::mpl::identity< char > {}; + template <> struct stream_char_common< boost::uint128_type >: public boost::mpl::identity< char > {}; +#endif + +#if !defined(BOOST_LCAST_NO_WCHAR_T) && defined(BOOST_NO_INTRINSIC_WCHAR_T) + template <> + struct stream_char_common< wchar_t > + { + typedef char type; + }; +#endif + } + + namespace detail // deduce_source_char_impl<T> + { + // If type T is `deduce_character_type_later` type, then tries to deduce + // character type using boost::has_left_shift<T> metafunction. + // Otherwise supplied type T is a character type, that must be normalized + // using normalize_single_byte_char<Char>. + // Executed at Stage 2 (See deduce_source_char<T> and deduce_target_char<T>) + template < class Char > + struct deduce_source_char_impl + { + typedef BOOST_DEDUCED_TYPENAME boost::detail::normalize_single_byte_char< Char >::type type; + }; + + template < class T > + struct deduce_source_char_impl< deduce_character_type_later< T > > + { + typedef boost::has_left_shift< std::basic_ostream< char >, T > result_t; + +#if defined(BOOST_LCAST_NO_WCHAR_T) + BOOST_STATIC_ASSERT_MSG((result_t::value), + "Source type is not std::ostream`able and std::wostream`s are not supported by your STL implementation"); + typedef char type; +#else + typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_c< + result_t::value, char, wchar_t + >::type type; + + BOOST_STATIC_ASSERT_MSG((result_t::value || boost::has_left_shift< std::basic_ostream< type >, T >::value), + "Source type is neither std::ostream`able nor std::wostream`able"); +#endif + }; + } + + namespace detail // deduce_target_char_impl<T> + { + // If type T is `deduce_character_type_later` type, then tries to deduce + // character type using boost::has_right_shift<T> metafunction. + // Otherwise supplied type T is a character type, that must be normalized + // using normalize_single_byte_char<Char>. + // Executed at Stage 2 (See deduce_source_char<T> and deduce_target_char<T>) + template < class Char > + struct deduce_target_char_impl + { + typedef BOOST_DEDUCED_TYPENAME normalize_single_byte_char< Char >::type type; + }; + + template < class T > + struct deduce_target_char_impl< deduce_character_type_later<T> > + { + typedef boost::has_right_shift<std::basic_istream<char>, T > result_t; + +#if defined(BOOST_LCAST_NO_WCHAR_T) + BOOST_STATIC_ASSERT_MSG((result_t::value), + "Target type is not std::istream`able and std::wistream`s are not supported by your STL implementation"); + typedef char type; +#else + typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_c< + result_t::value, char, wchar_t + >::type type; + + BOOST_STATIC_ASSERT_MSG((result_t::value || boost::has_right_shift<std::basic_istream<wchar_t>, T >::value), + "Target type is neither std::istream`able nor std::wistream`able"); +#endif + }; + } + + namespace detail // deduce_target_char<T> and deduce_source_char<T> + { + // We deduce stream character types in two stages. + // + // Stage 1 is common for Target and Source. At Stage 1 we get + // non normalized character type (may contain unsigned/signed char) + // or deduce_character_type_later<T> where T is the original type. + // Stage 1 is executed by stream_char_common<T> + // + // At Stage 2 we normalize character types or try to deduce character + // type using metafunctions. + // Stage 2 is executed by deduce_target_char_impl<T> and + // deduce_source_char_impl<T> + // + // deduce_target_char<T> and deduce_source_char<T> functions combine + // both stages + + template < class T > + struct deduce_target_char + { + typedef BOOST_DEDUCED_TYPENAME stream_char_common< T >::type stage1_type; + typedef BOOST_DEDUCED_TYPENAME deduce_target_char_impl< stage1_type >::type stage2_type; + + typedef stage2_type type; + }; + + template < class T > + struct deduce_source_char + { + typedef BOOST_DEDUCED_TYPENAME stream_char_common< T >::type stage1_type; + typedef BOOST_DEDUCED_TYPENAME deduce_source_char_impl< stage1_type >::type stage2_type; + + typedef stage2_type type; + }; + } + + namespace detail // extract_char_traits template + { + // We are attempting to get char_traits<> from T + // template parameter. Otherwise we'll be using std::char_traits<Char> + template < class Char, class T > + struct extract_char_traits + : boost::false_type + { + typedef std::char_traits< Char > trait_t; + }; + + template < class Char, class Traits, class Alloc > + struct extract_char_traits< Char, std::basic_string< Char, Traits, Alloc > > + : boost::true_type + { + typedef Traits trait_t; + }; + + template < class Char, class Traits, class Alloc> + struct extract_char_traits< Char, boost::container::basic_string< Char, Traits, Alloc > > + : boost::true_type + { + typedef Traits trait_t; + }; + } + + namespace detail // array_to_pointer_decay<T> + { + template<class T> + struct array_to_pointer_decay + { + typedef T type; + }; + + template<class T, std::size_t N> + struct array_to_pointer_decay<T[N]> + { + typedef const T * type; + }; + } + + namespace detail // is_this_float_conversion_optimized<Float, Char> + { + // this metafunction evaluates to true, if we have optimized comnversion + // from Float type to Char array. + // Must be in sync with lexical_stream_limited_src<Char, ...>::shl_real_type(...) + template <typename Float, typename Char> + struct is_this_float_conversion_optimized + { + typedef boost::type_traits::ice_and< + boost::is_float<Float>::value, +#if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_SWPRINTF) && !defined(__MINGW32__) + boost::type_traits::ice_or< + boost::type_traits::ice_eq<sizeof(Char), sizeof(char) >::value, + boost::is_same<Char, wchar_t>::value + >::value +#else + boost::type_traits::ice_eq<sizeof(Char), sizeof(char) >::value +#endif + > result_type; + + BOOST_STATIC_CONSTANT(bool, value = (result_type::value) ); + }; + } + + namespace detail // lcast_src_length + { + // Return max. length of string representation of Source; + template< class Source, // Source type of lexical_cast. + class Enable = void // helper type + > + struct lcast_src_length + { + BOOST_STATIC_CONSTANT(std::size_t, value = 1); + }; + + // Helper for integral types. + // Notes on length calculation: + // Max length for 32bit int with grouping "\1" and thousands_sep ',': + // "-2,1,4,7,4,8,3,6,4,7" + // ^ - is_signed + // ^ - 1 digit not counted by digits10 + // ^^^^^^^^^^^^^^^^^^ - digits10 * 2 + // + // Constant is_specialized is used instead of constant 1 + // to prevent buffer overflow in a rare case when + // <boost/limits.hpp> doesn't add missing specialization for + // numeric_limits<T> for some integral type T. + // When is_specialized is false, the whole expression is 0. + template <class Source> + struct lcast_src_length< + Source, BOOST_DEDUCED_TYPENAME boost::enable_if<boost::is_integral<Source> >::type + > + { +#ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS + BOOST_STATIC_CONSTANT(std::size_t, value = + std::numeric_limits<Source>::is_signed + + std::numeric_limits<Source>::is_specialized + /* == 1 */ + std::numeric_limits<Source>::digits10 * 2 + ); +#else + BOOST_STATIC_CONSTANT(std::size_t, value = 156); + BOOST_STATIC_ASSERT(sizeof(Source) * CHAR_BIT <= 256); +#endif + }; + +#ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION + // Helper for floating point types. + // -1.23456789e-123456 + // ^ sign + // ^ leading digit + // ^ decimal point + // ^^^^^^^^ lcast_precision<Source>::value + // ^ "e" + // ^ exponent sign + // ^^^^^^ exponent (assumed 6 or less digits) + // sign + leading digit + decimal point + "e" + exponent sign == 5 + template<class Source> + struct lcast_src_length< + Source, BOOST_DEDUCED_TYPENAME boost::enable_if<boost::is_float<Source> >::type + > + { + BOOST_STATIC_ASSERT( + std::numeric_limits<Source>::max_exponent10 <= 999999L && + std::numeric_limits<Source>::min_exponent10 >= -999999L + ); + + BOOST_STATIC_CONSTANT(std::size_t, value = + 5 + lcast_precision<Source>::value + 6 + ); + }; +#endif // #ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION + } + + namespace detail // lexical_cast_stream_traits<Source, Target> + { + template <class Source, class Target> + struct lexical_cast_stream_traits { + typedef BOOST_DEDUCED_TYPENAME boost::detail::array_to_pointer_decay<Source>::type src; + typedef BOOST_DEDUCED_TYPENAME boost::remove_cv<src>::type no_cv_src; + + typedef boost::detail::deduce_source_char<no_cv_src> deduce_src_char_metafunc; + typedef BOOST_DEDUCED_TYPENAME deduce_src_char_metafunc::type src_char_t; + typedef BOOST_DEDUCED_TYPENAME boost::detail::deduce_target_char<Target>::type target_char_t; + + typedef BOOST_DEDUCED_TYPENAME boost::detail::widest_char< + target_char_t, src_char_t + >::type char_type; + +#if !defined(BOOST_NO_CXX11_CHAR16_T) && defined(BOOST_NO_CXX11_UNICODE_LITERALS) + BOOST_STATIC_ASSERT_MSG(( !boost::is_same<char16_t, src_char_t>::value + && !boost::is_same<char16_t, target_char_t>::value), + "Your compiler does not have full support for char16_t" ); +#endif +#if !defined(BOOST_NO_CXX11_CHAR32_T) && defined(BOOST_NO_CXX11_UNICODE_LITERALS) + BOOST_STATIC_ASSERT_MSG(( !boost::is_same<char32_t, src_char_t>::value + && !boost::is_same<char32_t, target_char_t>::value), + "Your compiler does not have full support for char32_t" ); +#endif + + typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_c< + boost::detail::extract_char_traits<char_type, Target>::value, + BOOST_DEDUCED_TYPENAME boost::detail::extract_char_traits<char_type, Target>, + BOOST_DEDUCED_TYPENAME boost::detail::extract_char_traits<char_type, no_cv_src> + >::type::trait_t traits; + + typedef boost::type_traits::ice_and< + boost::is_same<char, src_char_t>::value, // source is not a wide character based type + boost::type_traits::ice_ne<sizeof(char), sizeof(target_char_t) >::value, // target type is based on wide character + boost::type_traits::ice_not< + boost::detail::is_character<no_cv_src>::value // single character widening is optimized + >::value // and does not requires stringbuffer + > is_string_widening_required_t; + + typedef boost::type_traits::ice_not< boost::type_traits::ice_or< + boost::is_integral<no_cv_src>::value, + boost::detail::is_this_float_conversion_optimized<no_cv_src, char_type >::value, + boost::detail::is_character< + BOOST_DEDUCED_TYPENAME deduce_src_char_metafunc::stage1_type // if we did not get character type at stage1 + >::value // then we have no optimization for that type + >::value > is_source_input_not_optimized_t; + + // If we have an optimized conversion for + // Source, we do not need to construct stringbuf. + BOOST_STATIC_CONSTANT(bool, requires_stringbuf = + (boost::type_traits::ice_or< + is_string_widening_required_t::value, is_source_input_not_optimized_t::value + >::value) + ); + + typedef boost::detail::lcast_src_length<no_cv_src> len_t; + }; + } + + namespace detail + { + template<typename Target, typename Source> + struct lexical_converter_impl + { + typedef lexical_cast_stream_traits<Source, Target> stream_trait; + + typedef detail::lexical_istream_limited_src< + BOOST_DEDUCED_TYPENAME stream_trait::char_type, + BOOST_DEDUCED_TYPENAME stream_trait::traits, + stream_trait::requires_stringbuf, + stream_trait::len_t::value + 1 + > i_interpreter_type; + + typedef detail::lexical_ostream_limited_src< + BOOST_DEDUCED_TYPENAME stream_trait::char_type, + BOOST_DEDUCED_TYPENAME stream_trait::traits + > o_interpreter_type; + + static inline bool try_convert(const Source& arg, Target& result) { + i_interpreter_type i_interpreter; + + // Disabling ADL, by directly specifying operators. + if (!(i_interpreter.operator <<(arg))) + return false; + + o_interpreter_type out(i_interpreter.cbegin(), i_interpreter.cend()); + + // Disabling ADL, by directly specifying operators. + if(!(out.operator >>(result))) + return false; + + return true; + } + }; + } + +} // namespace boost + +#undef BOOST_LCAST_NO_WCHAR_T + +#endif // BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_HPP + |