usestd::error::Error as ErrorTrait;usestd::fmt;#[derive(Debug)]pubstructParseError;implErrorTrait forParseError{}implfmt::Display forParseError{//This trait requires `fmt` with this exact signature.
fnfmt(&self, f:&mutfmt::Formatter)->fmt::Result{// Write strictly the first element into the supplied output
// stream: `f`. Returns `fmt::Result` which indicates whether the
// operation succeeded or failed. Note that `write!` uses syntax which
// is very similar to `println!`.
write!(f,"{}",self)}}