Chris@102: // Copyright Kevlin Henney, 2000-2005.
Chris@102: // Copyright Alexander Nasonov, 2006-2010.
Chris@102: // Copyright Antony Polukhin, 2011-2014.
Chris@102: //
Chris@102: // Distributed under the Boost Software License, Version 1.0. (See
Chris@102: // accompanying file LICENSE_1_0.txt or copy at
Chris@102: // http://www.boost.org/LICENSE_1_0.txt)
Chris@102: //
Chris@102: // what:  lexical_cast custom keyword cast
Chris@102: // who:   contributed by Kevlin Henney,
Chris@102: //        enhanced with contributions from Terje Slettebo,
Chris@102: //        with additional fixes and suggestions from Gennaro Prota,
Chris@102: //        Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
Chris@102: //        Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann,
Chris@102: //        Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters
Chris@102: // when:  November 2000, March 2003, June 2005, June 2006, March 2011 - 2014
Chris@102: 
Chris@102: #ifndef BOOST_LEXICAL_CAST_LEXICAL_CAST_OLD_HPP
Chris@102: #define BOOST_LEXICAL_CAST_LEXICAL_CAST_OLD_HPP
Chris@102: 
Chris@102: #include <boost/config.hpp>
Chris@102: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@102: #   pragma once
Chris@102: #endif
Chris@102: 
Chris@102: #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING)
Chris@102: #define BOOST_LCAST_NO_WCHAR_T
Chris@102: #endif
Chris@102: 
Chris@102: #include <climits>
Chris@102: #include <cstddef>
Chris@102: #include <string>
Chris@102: #include <cstring>
Chris@102: #include <cstdio>
Chris@102: #include <boost/limits.hpp>
Chris@102: #include <boost/mpl/if.hpp>
Chris@102: #include <boost/type_traits/ice.hpp>
Chris@102: #include <boost/type_traits/is_pointer.hpp>
Chris@102: #include <boost/static_assert.hpp>
Chris@102: #include <boost/detail/lcast_precision.hpp>
Chris@102: #include <boost/detail/workaround.hpp>
Chris@102: 
Chris@102: #ifdef BOOST_NO_STRINGSTREAM
Chris@102: #include <strstream>
Chris@102: #else
Chris@102: #include <sstream>
Chris@102: #endif
Chris@102: 
Chris@102: #include <boost/lexical_cast/bad_lexical_cast.hpp>
Chris@102: #include <boost/lexical_cast/detail/widest_char.hpp>
Chris@102: 
Chris@102: namespace boost {
Chris@102:     namespace detail
Chris@102:     {
Chris@102: 
Chris@102:         // selectors for choosing stream character type
Chris@102:         template<typename Type>
Chris@102:         struct stream_char
Chris@102:         {
Chris@102:             typedef char type;
Chris@102:         };
Chris@102: 
Chris@102: #ifndef BOOST_LCAST_NO_WCHAR_T
Chris@102: #ifndef BOOST_NO_INTRINSIC_WCHAR_T
Chris@102:         template<>
Chris@102:         struct stream_char<wchar_t>
Chris@102:         {
Chris@102:             typedef wchar_t type;
Chris@102:         };
Chris@102: #endif
Chris@102: 
Chris@102:         template<>
Chris@102:         struct stream_char<wchar_t *>
Chris@102:         {
Chris@102:             typedef wchar_t type;
Chris@102:         };
Chris@102: 
Chris@102:         template<>
Chris@102:         struct stream_char<const wchar_t *>
Chris@102:         {
Chris@102:             typedef wchar_t type;
Chris@102:         };
Chris@102: 
Chris@102:         template<>
Chris@102:         struct stream_char<std::wstring>
Chris@102:         {
Chris@102:             typedef wchar_t type;
Chris@102:         };
Chris@102: #endif
Chris@102: 
Chris@102:         // stream wrapper for handling lexical conversions
Chris@102:         template<typename Target, typename Source, typename Traits>
Chris@102:         class lexical_stream
Chris@102:         {
Chris@102:         private:
Chris@102:             typedef typename widest_char<
Chris@102:                 typename stream_char<Target>::type,
Chris@102:                 typename stream_char<Source>::type>::type char_type;
Chris@102: 
Chris@102:             typedef Traits traits_type;
Chris@102: 
Chris@102:         public:
Chris@102:             lexical_stream(char_type* = 0, char_type* = 0)
Chris@102:             {
Chris@102:                 stream.unsetf(std::ios::skipws);
Chris@102:                 lcast_set_precision(stream, static_cast<Source*>(0), static_cast<Target*>(0) );
Chris@102:             }
Chris@102:             ~lexical_stream()
Chris@102:             {
Chris@102:                 #if defined(BOOST_NO_STRINGSTREAM)
Chris@102:                 stream.freeze(false);
Chris@102:                 #endif
Chris@102:             }
Chris@102:             bool operator<<(const Source &input)
Chris@102:             {
Chris@102:                 return !(stream << input).fail();
Chris@102:             }
Chris@102:             template<typename InputStreamable>
Chris@102:             bool operator>>(InputStreamable &output)
Chris@102:             {
Chris@102:                 return !is_pointer<InputStreamable>::value &&
Chris@102:                        stream >> output &&
Chris@102:                        stream.get() == traits_type::eof();
Chris@102:             }
Chris@102: 
Chris@102:             bool operator>>(std::string &output)
Chris@102:             {
Chris@102:                 #if defined(BOOST_NO_STRINGSTREAM)
Chris@102:                 stream << '\0';
Chris@102:                 #endif
Chris@102:                 stream.str().swap(output);
Chris@102:                 return true;
Chris@102:             }
Chris@102:             #ifndef BOOST_LCAST_NO_WCHAR_T
Chris@102:             bool operator>>(std::wstring &output)
Chris@102:             {
Chris@102:                 stream.str().swap(output);
Chris@102:                 return true;
Chris@102:             }
Chris@102:             #endif
Chris@102: 
Chris@102:         private:
Chris@102:             #if defined(BOOST_NO_STRINGSTREAM)
Chris@102:             std::strstream stream;
Chris@102:             #elif defined(BOOST_NO_STD_LOCALE)
Chris@102:             std::stringstream stream;
Chris@102:             #else
Chris@102:             std::basic_stringstream<char_type,traits_type> stream;
Chris@102:             #endif
Chris@102:         };
Chris@102:     }
Chris@102: 
Chris@102:     // call-by-value fallback version (deprecated)
Chris@102: 
Chris@102:     template<typename Target, typename Source>
Chris@102:     Target lexical_cast(Source arg)
Chris@102:     {
Chris@102:         typedef typename detail::widest_char< 
Chris@102:             BOOST_DEDUCED_TYPENAME detail::stream_char<Target>::type 
Chris@102:           , BOOST_DEDUCED_TYPENAME detail::stream_char<Source>::type 
Chris@102:         >::type char_type; 
Chris@102: 
Chris@102:         typedef std::char_traits<char_type> traits;
Chris@102:         detail::lexical_stream<Target, Source, traits> interpreter;
Chris@102:         Target result;
Chris@102: 
Chris@102:         if(!(interpreter << arg && interpreter >> result))
Chris@102:             boost::conversion::detail::throw_bad_cast<Source, Target>();
Chris@102:         return result;
Chris@102:     }
Chris@102: 
Chris@102: } // namespace boost
Chris@102: 
Chris@102: #undef BOOST_LCAST_NO_WCHAR_T
Chris@102: 
Chris@102: #endif // BOOST_LEXICAL_CAST_LEXICAL_CAST_OLD_HPP
Chris@102: