boost/format/free_funcs.hpp

// -*- C++ -*-
//  Boost general library 'format'   ---------------------------
//  See http://www.boost.org for updates, documentation, and revision history.

//  (C) Samuel Krempp 2001
//  Permission to copy, use, modify, sell and
//  distribute this software is granted provided this copyright notice appears
//  in all copies. This software is provided "as is" without express or implied
//  warranty, and with no claim as to its suitability for any purpose.

// ideas taken from R�diger Loos's format class
// and Karl Nelson's ofstream (also took its parsing code as basis for printf parsing)

// ------------------------------------------------------------------------------
// free_funcs.hpp :  implementation of the free functions declared in namespace format
// ------------------------------------------------------------------------------

#ifndef BOOST_FORMAT_FUNCS_HPP
#define BOOST_FORMAT_FUNCS_HPP

#include <boost/format/format_class.hpp>
#include <boost/throw_exception.hpp>

namespace boost {

    template<class Ch, class Tr> inline 
    std::basic_string<Ch, Tr> str(const basic_format<Ch, Tr>& f) {
        // adds up all pieces of strings and converted items, and return the formatted string
        return f.str();
    }


    template< class Ch, class Tr>
    BOOST_IO_STD basic_ostream<Ch, Tr>& 
    operator<<( BOOST_IO_STD basic_ostream<Ch, Tr>& os, 
                const boost::basic_format<Ch, Tr>& f) 
        // effect: "return os << str(f);" but we can try to do it faster
    {
        typedef boost::basic_format<Ch, Tr>   format_t;
        if(f.items_.size()==0) 
            os << f.prefix_;
        else {
            if(f.cur_arg_ < f.num_args_)
                if( f.exceptions() & io::too_few_args_bit )
                    boost::throw_exception(io::too_few_args()); // not enough variables supplied
            if(f.style_ & format_t::special_needs) 
                os << f.str();
            else {
                // else we dont have to count chars output, so we dump directly to os :
                os << f.prefix_;
                for(unsigned long i=0; i<f.items_.size(); ++i) {
                    const typename format_t::format_item_t& item = f.items_[i];
                    os << item.res_;
                    os << item.appendix_;
                }
            }
        }
        f.dumped_=true;
        return os;
    }

} // namespace boost


#endif // BOOST_FORMAT_FUNCS_HPP

Boost C++ Libraries

boost/format/free_funcs.hpp