guix-devel/nix/boost/format/format_class.hpp

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

//  (C) Samuel Krempp 2001
//                  krempp@crans.ens-cachan.fr
//  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)

// ------------------------------------------------------------------------------
// format_class.hpp :  class interface
// ------------------------------------------------------------------------------


#ifndef BOOST_FORMAT_CLASS_HPP
#define BOOST_FORMAT_CLASS_HPP

#include <vector>
#include <string>

#include <boost/format/format_fwd.hpp>
#include <boost/format/internals_fwd.hpp>

#include <boost/format/internals.hpp>

namespace boost {

class basic_format 
{
public:
  typedef std::string                string_t;
  typedef BOOST_IO_STD ostringstream internal_stream_t;
private:
  typedef BOOST_IO_STD ostream       stream_t;
  typedef io::detail::stream_format_state  stream_format_state;
  typedef io::detail::format_item          format_item_t;

public:
  basic_format(const char* str);
  basic_format(const string_t& s);
#ifndef BOOST_NO_STD_LOCALE
  basic_format(const char* str, const std::locale & loc);
  basic_format(const string_t& s, const std::locale & loc);
#endif // no locale
  basic_format(const basic_format& x);
  basic_format& operator= (const basic_format& x);

  basic_format& clear(); // empty the string buffers (except bound arguments, see clear_binds() )

  // pass arguments through those operators :
  template<class T>  basic_format&   operator%(const T& x) 
  { 
    return io::detail::feed<const T&>(*this,x);
  }

#ifndef BOOST_NO_OVERLOAD_FOR_NON_CONST
  template<class T>  basic_format&   operator%(T& x) 
  {
    return io::detail::feed<T&>(*this,x);
  }
#endif


  // system for binding arguments :
  template<class T>  
  basic_format&         bind_arg(int argN, const T& val) 
  {
    return io::detail::bind_arg_body(*this, argN, val); 
  }
  basic_format&         clear_bind(int argN);
  basic_format&         clear_binds();

  // modify the params of a directive, by applying a manipulator :
  template<class T> 
  basic_format&  modify_item(int itemN, const T& manipulator) 
  {
    return io::detail::modify_item_body(*this, itemN, manipulator) ;
  }

  // Choosing which errors will throw exceptions :
  unsigned char exceptions() const;
  unsigned char exceptions(unsigned char newexcept);

  // final output
  string_t str() const;
  friend BOOST_IO_STD ostream& 
  operator<< ( BOOST_IO_STD ostream& , const basic_format& ); 
                      

  template<class T>  friend basic_format&  
  io::detail::feed(basic_format&, T);
    
  template<class T>  friend   
  void io::detail::distribute(basic_format&, T);
  
  template<class T>  friend
  basic_format&  io::detail::modify_item_body(basic_format&, int, const T&);

  template<class T> friend
  basic_format&  io::detail::bind_arg_body(basic_format&, int, const T&);

// make the members private only if the friend templates are supported
private:

  // flag bits, used for style_
  enum style_values  { ordered = 1,        // set only if all directives are  positional directives
                       special_needs = 4 };     

  // parse the format string :
  void parse(const string_t&);

  int                           style_;         // style of format-string :  positional or not, etc
  int                           cur_arg_;       // keep track of wich argument will come
  int                           num_args_;      // number of expected arguments
  mutable bool                  dumped_;        // true only after call to str() or <<
  std::vector<format_item_t>    items_;         // vector of directives (aka items)
  string_t                      prefix_;        // piece of string to insert before first item

  std::vector<bool>             bound_;         // stores which arguments were bound
                                                //   size = num_args OR zero
  internal_stream_t             oss_;           // the internal stream.
  stream_format_state           state0_;        // reference state for oss_
  unsigned char                 exceptions_;
}; // class basic_format


} // namespace boost


#endif // BOOST_FORMAT_CLASS_HPP