Chris@16: // tuple_io.hpp --------------------------------------------------------------
Chris@16: 
Chris@16: // Copyright (C) 2001 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
Chris@16: //               2001 Gary Powell (gary.powell@sierra.com)
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: // For more information, see http://www.boost.org 
Chris@16: 
Chris@16: // ----------------------------------------------------------------------------
Chris@16: 
Chris@16: #ifndef BOOST_TUPLE_IO_HPP
Chris@16: #define BOOST_TUPLE_IO_HPP
Chris@16: 
Chris@16: #include <istream>
Chris@16: #include <ostream>
Chris@16: 
Chris@16: #include <sstream>
Chris@16: 
Chris@16: #include "boost/tuple/tuple.hpp"
Chris@16: 
Chris@16: // This is ugly: one should be using twoargument isspace since whitspace can
Chris@16: // be locale dependent, in theory at least.
Chris@16: // not all libraries implement have the two-arg version, so we need to 
Chris@16: // use the one-arg one, which one should get with <cctype> but there seem
Chris@16: // to be exceptions to this.
Chris@16: 
Chris@16: #if !defined (BOOST_NO_STD_LOCALE)
Chris@16: 
Chris@16: #include <locale> // for two-arg isspace
Chris@16: 
Chris@16: #else 
Chris@16: 
Chris@16: #include <cctype> // for one-arg (old) isspace 
Chris@16: #include <ctype.h> // Metrowerks does not find one-arg isspace from cctype
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace tuples {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: class format_info {
Chris@16: public:   
Chris@16: 
Chris@16:    enum manipulator_type { open, close, delimiter };
Chris@16:    BOOST_STATIC_CONSTANT(int, number_of_manipulators = delimiter + 1);
Chris@16: private:
Chris@16:    
Chris@16:    static int get_stream_index (int m)
Chris@16:    {
Chris@16:      static const int stream_index[number_of_manipulators]
Chris@16:         = { std::ios::xalloc(), std::ios::xalloc(), std::ios::xalloc() };
Chris@16: 
Chris@16:      return stream_index[m];
Chris@16:    }
Chris@16: 
Chris@16:    format_info(const format_info&);
Chris@16:    format_info();   
Chris@16: 
Chris@16: 
Chris@16: public:
Chris@16: 
Chris@16:    template<class CharType, class CharTrait>
Chris@16:    static CharType get_manipulator(std::basic_ios<CharType, CharTrait>& i, 
Chris@16:                                    manipulator_type m) {
Chris@16:      // The manipulators are stored as long.
Chris@16:      // A valid instanitation of basic_stream allows CharType to be any POD,
Chris@16:      // hence, the static_cast may fail (it fails if long is not convertible 
Chris@16:      // to CharType
Chris@16:      CharType c = static_cast<CharType>(i.iword(get_stream_index(m)) ); 
Chris@16:      // parentheses and space are the default manipulators
Chris@16:      if (!c) {
Chris@16:        switch(m) {
Chris@16:          case detail::format_info::open :  c = i.widen('('); break;
Chris@16:          case detail::format_info::close : c = i.widen(')'); break;
Chris@16:          case detail::format_info::delimiter : c = i.widen(' '); break;
Chris@16:        }
Chris@16:      }
Chris@16:      return c;
Chris@16:    }
Chris@16: 
Chris@16: 
Chris@16:    template<class CharType, class CharTrait>
Chris@16:    static void set_manipulator(std::basic_ios<CharType, CharTrait>& i, 
Chris@16:                                manipulator_type m, CharType c) {
Chris@16:      // The manipulators are stored as long.
Chris@16:      // A valid instanitation of basic_stream allows CharType to be any POD,
Chris@16:      // hence, the static_cast may fail (it fails if CharType is not 
Chris@16:      // convertible long.
Chris@16:       i.iword(get_stream_index(m)) = static_cast<long>(c);
Chris@16:    }
Chris@16: };
Chris@16: 
Chris@16: } // end of namespace detail
Chris@16:  
Chris@16: template<class CharType>    
Chris@16: class tuple_manipulator {
Chris@16:   const detail::format_info::manipulator_type mt;
Chris@16:   CharType f_c;
Chris@16: public:
Chris@16:   explicit tuple_manipulator(detail::format_info::manipulator_type m, 
Chris@16:                              const char c = 0)
Chris@16:      : mt(m), f_c(c) {}
Chris@16:   
Chris@16:    template<class CharTrait>
Chris@16:   void set(std::basic_ios<CharType, CharTrait> &io) const {
Chris@16:      detail::format_info::set_manipulator(io, mt, f_c);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_ostream<CharType, CharTrait>&
Chris@16: operator<<(std::basic_ostream<CharType, CharTrait>& o, const tuple_manipulator<CharType>& m) {
Chris@16:   m.set(o);
Chris@16:   return o;
Chris@16: }
Chris@16: 
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_istream<CharType, CharTrait>&
Chris@16: operator>>(std::basic_istream<CharType, CharTrait>& i, const tuple_manipulator<CharType>& m) {
Chris@16:   m.set(i);
Chris@16:   return i;
Chris@16: }
Chris@16: 
Chris@16:    
Chris@16: template<class CharType>
Chris@16: inline tuple_manipulator<CharType> set_open(const CharType c) {
Chris@16:    return tuple_manipulator<CharType>(detail::format_info::open, c);
Chris@16: }
Chris@16: 
Chris@16: template<class CharType>
Chris@16: inline tuple_manipulator<CharType> set_close(const CharType c) {
Chris@16:    return tuple_manipulator<CharType>(detail::format_info::close, c);
Chris@16: }
Chris@16: 
Chris@16: template<class CharType>
Chris@16: inline tuple_manipulator<CharType> set_delimiter(const CharType c) {
Chris@16:    return tuple_manipulator<CharType>(detail::format_info::delimiter, c);
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16:    
Chris@16:    
Chris@16: // -------------------------------------------------------------
Chris@16: // printing tuples to ostream in format (a b c)
Chris@16: // parentheses and space are defaults, but can be overriden with manipulators
Chris@16: // set_open, set_close and set_delimiter
Chris@16:    
Chris@16: namespace detail {
Chris@16: 
Chris@16: // Note: The order of the print functions is critical 
Chris@16: // to let a conforming compiler  find and select the correct one.
Chris@16: 
Chris@16: 
Chris@16: template<class CharType, class CharTrait, class T1>
Chris@16: inline std::basic_ostream<CharType, CharTrait>& 
Chris@16: print(std::basic_ostream<CharType, CharTrait>& o, const cons<T1, null_type>& t) {
Chris@16:   return o << t.head;
Chris@16: }
Chris@16: 
Chris@16:  
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_ostream<CharType, CharTrait>& 
Chris@16: print(std::basic_ostream<CharType, CharTrait>& o, const null_type&) { 
Chris@16:   return o; 
Chris@16: }
Chris@16: 
Chris@16: template<class CharType, class CharTrait, class T1, class T2>
Chris@16: inline std::basic_ostream<CharType, CharTrait>& 
Chris@16: print(std::basic_ostream<CharType, CharTrait>& o, const cons<T1, T2>& t) {
Chris@16:   
Chris@16:   const CharType d = format_info::get_manipulator(o, format_info::delimiter);
Chris@16:    
Chris@16:   o << t.head;
Chris@16: 
Chris@16:   o << d;
Chris@16: 
Chris@16:   return print(o, t.tail);
Chris@16: }
Chris@16: 
Chris@16: template<class CharT, class Traits, class T>
Chris@16: inline bool handle_width(std::basic_ostream<CharT, Traits>& o, const T& t) {
Chris@16:     std::streamsize width = o.width();
Chris@16:     if(width == 0) return false;
Chris@16: 
Chris@16:     std::basic_ostringstream<CharT, Traits> ss;
Chris@16: 
Chris@16:     ss.copyfmt(o);
Chris@16:     ss.tie(0);
Chris@16:     ss.width(0);
Chris@16: 
Chris@16:     ss << t;
Chris@16:     o << ss.str();
Chris@16: 
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: 
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_ostream<CharType, CharTrait>& 
Chris@16: operator<<(std::basic_ostream<CharType, CharTrait>& o, 
Chris@16:            const null_type& t) {
Chris@16:   if (!o.good() ) return o;
Chris@16:   if (detail::handle_width(o, t)) return o;
Chris@16:  
Chris@16:   const CharType l = 
Chris@16:     detail::format_info::get_manipulator(o, detail::format_info::open);
Chris@16:   const CharType r = 
Chris@16:     detail::format_info::get_manipulator(o, detail::format_info::close);
Chris@16:    
Chris@16:   o << l;
Chris@16:   o << r;
Chris@16: 
Chris@16:   return o;
Chris@16: }
Chris@16: 
Chris@16: template<class CharType, class CharTrait, class T1, class T2>
Chris@16: inline std::basic_ostream<CharType, CharTrait>& 
Chris@16: operator<<(std::basic_ostream<CharType, CharTrait>& o, 
Chris@16:            const cons<T1, T2>& t) {
Chris@16:   if (!o.good() ) return o;
Chris@16:   if (detail::handle_width(o, t)) return o;
Chris@16:  
Chris@16:   const CharType l = 
Chris@16:     detail::format_info::get_manipulator(o, detail::format_info::open);
Chris@16:   const CharType r = 
Chris@16:     detail::format_info::get_manipulator(o, detail::format_info::close);
Chris@16:    
Chris@16:   o << l;   
Chris@16: 
Chris@16:   detail::print(o, t);  
Chris@16: 
Chris@16:   o << r;
Chris@16: 
Chris@16:   return o;
Chris@16: }
Chris@16: 
Chris@16:    
Chris@16: // -------------------------------------------------------------
Chris@16: // input stream operators
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: 
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_istream<CharType, CharTrait>& 
Chris@16: extract_and_check_delimiter(
Chris@16:   std::basic_istream<CharType, CharTrait> &is, format_info::manipulator_type del)
Chris@16: {
Chris@16:   const CharType d = format_info::get_manipulator(is, del);
Chris@16: 
Chris@16: #if defined (BOOST_NO_STD_LOCALE)
Chris@16:   const bool is_delimiter = !isspace(d);
Chris@16: #elif defined ( __BORLANDC__ )
Chris@16:   const bool is_delimiter = !std::use_facet< std::ctype< CharType > >
Chris@16:     (is.getloc() ).is( std::ctype_base::space, d);
Chris@16: #else
Chris@16:   const bool is_delimiter = (!std::isspace(d, is.getloc()) );            
Chris@16: #endif
Chris@16: 
Chris@16:   CharType c;
Chris@16:   if (is_delimiter) { 
Chris@16:     is >> c;
Chris@16:     if (is.good() && c!=d) { 
Chris@16:       is.setstate(std::ios::failbit);
Chris@16:     }
Chris@16:   } else {
Chris@16:     is >> std::ws;
Chris@16:   }
Chris@16:   return is;
Chris@16: }
Chris@16: 
Chris@16:    
Chris@16: template<class CharType, class CharTrait, class T1>
Chris@16: inline  std::basic_istream<CharType, CharTrait> & 
Chris@16: read (std::basic_istream<CharType, CharTrait> &is, cons<T1, null_type>& t1) {
Chris@16: 
Chris@16:   if (!is.good()) return is;   
Chris@16:    
Chris@16:   return is >> t1.head; 
Chris@16: }
Chris@16: 
Chris@16: template<class CharType, class CharTrait, class T1, class T2>
Chris@16: inline std::basic_istream<CharType, CharTrait>& 
Chris@16: read(std::basic_istream<CharType, CharTrait> &is, cons<T1, T2>& t1) {
Chris@16: 
Chris@16:   if (!is.good()) return is;
Chris@16:    
Chris@16:   is >> t1.head;
Chris@16: 
Chris@16: 
Chris@16:   extract_and_check_delimiter(is, format_info::delimiter);
Chris@16: 
Chris@16:   return read(is, t1.tail);
Chris@16: }
Chris@16: 
Chris@16: } // end namespace detail
Chris@16: 
Chris@16: 
Chris@16: template<class CharType, class CharTrait>
Chris@16: inline std::basic_istream<CharType, CharTrait>& 
Chris@16: operator>>(std::basic_istream<CharType, CharTrait> &is, null_type&) {
Chris@16: 
Chris@16:   if (!is.good() ) return is;
Chris@16: 
Chris@16:   detail::extract_and_check_delimiter(is, detail::format_info::open);
Chris@16:   detail::extract_and_check_delimiter(is, detail::format_info::close);
Chris@16: 
Chris@16:   return is;
Chris@16: }
Chris@16: 
Chris@16: template<class CharType, class CharTrait, class T1, class T2>
Chris@16: inline std::basic_istream<CharType, CharTrait>& 
Chris@16: operator>>(std::basic_istream<CharType, CharTrait>& is, cons<T1, T2>& t1) {
Chris@16: 
Chris@16:   if (!is.good() ) return is;
Chris@16: 
Chris@16:   detail::extract_and_check_delimiter(is, detail::format_info::open);
Chris@16:                       
Chris@16:   detail::read(is, t1);
Chris@16:    
Chris@16:   detail::extract_and_check_delimiter(is, detail::format_info::close);
Chris@16: 
Chris@16:   return is;
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: } // end of namespace tuples
Chris@16: } // end of namespace boost
Chris@16: 
Chris@16: #endif // BOOST_TUPLE_IO_HPP
Chris@16: 
Chris@16: