C-style formatting for `streambuf' objects
==========================================

   The GNU `streambuf' class supports `printf'-like formatting and
scanning.

 - Method: int streambuf::form (const char *FORMAT, ...)
     Similar to `fprintf(FILE, FORMAT, ...)'.  The FORMAT is a
     `printf'-style format control string, which is used to format the
     (variable number of) arguments, printing the result on the `this'
     streambuf.  The result is the number of characters printed.

 - Method: int streambuf::vform (const char *FORMAT, va_list ARGS)
     Similar to `vfprintf(FILE, FORMAT, ARGS)'.  The FORMAT is a
     `printf'-style format control string, which is used to format the
     argument list ARGS, printing the result on the `this' streambuf.
     The result is the number of characters printed.

 - Method: int streambuf::scan (const char *FORMAT, ...)
     Similar to `fscanf(FILE, FORMAT, ...)'.  The FORMAT is a
     `scanf'-style format control string, which is used to read the
     (variable number of) arguments from the `this' streambuf.  The
     result is the number of items assigned, or `EOF' in case of input
     failure before any conversion.

 - Method: int streambuf::vscan (const char *FORMAT, va_list ARGS)
     Like `streambuf::scan', but takes a single `va_list' argument.