cast<RS, RT> method
Provides a Converter<RS, RT> view of this stream transformer.
If this transformer already has the desired type, or a subtype,
it is returned directly,
otherwise returns the result of retype<RS, RT>().
Implementation
Converter<RS, RT> cast<RS, RT>() {
Converter<Object, Object> self = this;
return self is Converter<RS, RT> ? self : retype<RS, RT>();
}