Function SCIPrationalToString 

pub unsafe extern "C" fn SCIPrationalToString(
    rational: *mut SCIP_RATIONAL,
    str_: *mut c_char,
    strlen: c_int,
) -> c_int

converts a rational to a string for printing, returns the number of copied characters.

@return number of characters printed into string, see also SCIPstrncpy()

@note If return value is equal to strlen, it means the string was truncated.