#ifndef EXCEPTIONSTREAM_H
#define EXCEPTIONSTREAM_H

#include <stdexcept>

#ifdef WIN32
    #undef ExceptionStream_NO_SSTREAM
    #define ExceptionStream_NO_SSTREAM
#endif

#ifdef ExceptionStream_NO_SSTREAM
    #include <fstream>
#else
    #include <sstream>
#endif

struct   exception_stream : public std::exception
/* This class provides an easy-to-use exception type for verbose error
messages.
Use like:
    ifstream    in( filename);
    if ( !in)
        throw exception_stream() << "Couldn't open file '" << filename << "'";
*/
{
    exception_stream();
    virtual const char* what()  const throw();  // Part of the std::exception interface.
    virtual ~exception_stream()  throw();
    
    template< class T>  friend const exception_stream&   operator << ( const exception_stream& es, const T& t);
    template< class T>  friend const exception_stream&   operator << ( const exception_stream& es, T& t);
    #ifdef WIN32
        template< class T>  friend const exception_stream&   operator << ( const exception_stream& es, const char* t);
        template< class T>  friend const exception_stream&   operator << ( const exception_stream& es, char* t);
    #endif
    exception_stream( const exception_stream& rhs);
    exception_stream& operator = ( const exception_stream& rhs);
    
    #ifdef ExceptionStream_NO_SSTREAM
      // Actually appends rhs.GetString() to *this. Should really clear *this first.
        private:
            std::string             filename;
            mutable std::ofstream   stream;
            mutable std::string     buffer;
    #else
        mutable std::stringstream   stream;
        mutable std::string         buffer_for_what;
    #endif
};


template< class T>
const exception_stream& operator << ( const exception_stream& es, const T& t)
{
    es.stream << t;
    return es;
}
template< class T>
const exception_stream& operator << ( const exception_stream& es, T& t)
{
    es.stream << t;
    return es;
}
#ifdef WIN32
    inline const exception_stream& operator << ( const exception_stream& es, const char* text)
    {
        es.stream << text;
        return es;
    }
    inline const exception_stream& operator << ( const exception_stream& es, char* text)
    {
        es.stream << text;
        return es;
    }
#endif

#endif