pub trait ErrorType {
type Error: Error;
}Expand description
Base trait for all IO traits, defining the error type.
All IO operations of all traits return the error defined in this trait.
Having a shared trait instead of having every trait define its own
Error associated type enforces all impls on the same type use the same error.
This is very convenient when writing generic code, it means you have to
handle a single error type T::Error, instead of <T as Read>::Error and <T as Write>::Error
which might be different types.