// Locale support (codecvt) -*- C++ -*- // Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 // Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 2, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. // // ISO C++ 14882: 22.2.1.5 Template class codecvt // // Written by Benjamin Kosnik <bkoz@redhat.com> /** @file bits/codecvt.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. */ #ifndef _CODECVT_H #define _CODECVT_H 1 #pragma GCC system_header /// @brief Empty base class for codecvt facet [22.2.1.5]. class codecvt_base { public: enum result { ok, partial, error, noconv }; }; /** * @brief Common base for codecvt functions. * * This template class provides implementations of the public functions * that forward to the protected virtual functions. * * This template also provides abstract stubs for the protected virtual * functions. */ template<typename _InternT, typename _ExternT, typename _StateT> class __codecvt_abstract_base : public locale::facet, public codecvt_base { public: // Types: typedef codecvt_base::result result; typedef _InternT intern_type; typedef _ExternT extern_type; typedef _StateT state_type; // 22.2.1.5.1 codecvt members /** * @brief Convert from internal to external character set. * * Converts input string of intern_type to output string of * extern_type. This is analogous to wcsrtombs. It does this by * calling codecvt::do_out. * * The source and destination character sets are determined by the * facet's locale, internal and external types. * * The characters in [from,from_end) are converted and written to * [to,to_end). from_next and to_next are set to point to the * character following the last successfully converted character, * respectively. If the result needed no conversion, from_next and * to_next are not affected. * * The @a state argument should be intialized if the input is at the * beginning and carried from a previous call if continuing * conversion. There are no guarantees about how @a state is used. * * The result returned is a member of codecvt_base::result. If * all the input is converted, returns codecvt_base::ok. If no * conversion is necessary, returns codecvt_base::noconv. If * the input ends early or there is insufficient space in the * output, returns codecvt_base::partial. Otherwise the * conversion failed and codecvt_base::error is returned. * * @param state Persistent conversion state data. * @param from Start of input. * @param from_end End of input. * @param from_next Returns start of unconverted data. * @param to Start of output buffer. * @param to_end End of output buffer. * @param to_next Returns start of unused output area. * @return codecvt_base::result. */ result out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { return this->do_out(__state, __from, __from_end, __from_next, __to, __to_end, __to_next); } /** * @brief Reset conversion state. * * Writes characters to output that would restore @a state to initial * conditions. The idea is that if a partial conversion occurs, then * the converting the characters written by this function would leave * the state in initial conditions, rather than partial conversion * state. It does this by calling codecvt::do_unshift(). * * For example, if 4 external characters always converted to 1 internal * character, and input to in() had 6 external characters with state * saved, this function would write two characters to the output and * set the state to initialized conditions. * * The source and destination character sets are determined by the * facet's locale, internal and external types. * * The result returned is a member of codecvt_base::result. If the * state could be reset and data written, returns codecvt_base::ok. If * no conversion is necessary, returns codecvt_base::noconv. If the * output has insufficient space, returns codecvt_base::partial. * Otherwise the reset failed and codecvt_base::error is returned. * * @param state Persistent conversion state data. * @param to Start of output buffer. * @param to_end End of output buffer. * @param to_next Returns start of unused output area. * @return codecvt_base::result. */ result unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { return this->do_unshift(__state, __to,__to_end,__to_next); } /** * @brief Convert from external to internal character set. * * Converts input string of extern_type to output string of * intern_type. This is analogous to mbsrtowcs. It does this by * calling codecvt::do_in. * * The source and destination character sets are determined by the * facet's locale, internal and external types. * * The characters in [from,from_end) are converted and written to * [to,to_end). from_next and to_next are set to point to the * character following the last successfully converted character, * respectively. If the result needed no conversion, from_next and * to_next are not affected. * * The @a state argument should be intialized if the input is at the * beginning and carried from a previous call if continuing * conversion. There are no guarantees about how @a state is used. * * The result returned is a member of codecvt_base::result. If * all the input is converted, returns codecvt_base::ok. If no * conversion is necessary, returns codecvt_base::noconv. If * the input ends early or there is insufficient space in the * output, returns codecvt_base::partial. Otherwise the * conversion failed and codecvt_base::error is returned. * * @param state Persistent conversion state data. * @param from Start of input. * @param from_end End of input. * @param from_next Returns start of unconverted data. * @param to Start of output buffer. * @param to_end End of output buffer. * @param to_next Returns start of unused output area. * @return codecvt_base::result. */ result in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const { return this->do_in(__state, __from, __from_end, __from_next, __to, __to_end, __to_next); } int encoding() const throw() { return this->do_encoding(); } bool always_noconv() const throw() { return this->do_always_noconv(); } int length(state_type& __state, const extern_type* __from, const extern_type* __end, size_t __max) const { return this->do_length(__state, __from, __end, __max); } int max_length() const throw() { return this->do_max_length(); } protected: explicit __codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { } virtual ~__codecvt_abstract_base() { } /** * @brief Convert from internal to external character set. * * Converts input string of intern_type to output string of * extern_type. This function is a hook for derived classes to change * the value returned. @see out for more information. */ virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const = 0; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const = 0; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const = 0; virtual int do_encoding() const throw() = 0; virtual bool do_always_noconv() const throw() = 0; virtual int do_length(state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const = 0; virtual int do_max_length() const throw() = 0; }; /// @brief class codecvt [22.2.1.5]. /// NB: Generic, mostly useless implementation. template<typename _InternT, typename _ExternT, typename _StateT> class codecvt : public __codecvt_abstract_base<_InternT, _ExternT, _StateT> { public: // Types: typedef codecvt_base::result result; typedef _InternT intern_type; typedef _ExternT extern_type; typedef _StateT state_type; protected: __c_locale _M_c_locale_codecvt; public: static locale::id id; explicit codecvt(size_t __refs = 0) : __codecvt_abstract_base<_InternT, _ExternT, _StateT> (__refs) { } explicit codecvt(__c_locale __cloc, size_t __refs = 0); protected: virtual ~codecvt() { } virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; template<typename _InternT, typename _ExternT, typename _StateT> locale::id codecvt<_InternT, _ExternT, _StateT>::id; /// @brief class codecvt<char, char, mbstate_t> specialization. template<> class codecvt<char, char, mbstate_t> : public __codecvt_abstract_base<char, char, mbstate_t> { public: // Types: typedef char intern_type; typedef char extern_type; typedef mbstate_t state_type; protected: __c_locale _M_c_locale_codecvt; public: static locale::id id; explicit codecvt(size_t __refs = 0); explicit codecvt(__c_locale __cloc, size_t __refs = 0); protected: virtual ~codecvt(); virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; #ifdef _GLIBCXX_USE_WCHAR_T /// @brief class codecvt<wchar_t, char, mbstate_t> specialization. template<> class codecvt<wchar_t, char, mbstate_t> : public __codecvt_abstract_base<wchar_t, char, mbstate_t> { public: // Types: typedef wchar_t intern_type; typedef char extern_type; typedef mbstate_t state_type; protected: __c_locale _M_c_locale_codecvt; public: static locale::id id; explicit codecvt(size_t __refs = 0); explicit codecvt(__c_locale __cloc, size_t __refs = 0); protected: virtual ~codecvt(); virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; #endif //_GLIBCXX_USE_WCHAR_T /// @brief class codecvt_byname [22.2.1.6]. template<typename _InternT, typename _ExternT, typename _StateT> class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT> { public: explicit codecvt_byname(const char* __s, size_t __refs = 0) : codecvt<_InternT, _ExternT, _StateT>(__refs) { if (std::strcmp(__s, "C") != 0 && std::strcmp(__s, "POSIX") != 0) { this->_S_destroy_c_locale(this->_M_c_locale_codecvt); this->_S_create_c_locale(this->_M_c_locale_codecvt, __s); } } protected: virtual ~codecvt_byname() { } }; #endif // _CODECVT_H