Type to represent URIs?

[Victor Porton]

Which type should I use to represent (absolute) URIs (or URLs)?

Is it OK to use `string` for this, or is there a better option?

I could also use URI class from my library:
https://github.com/vporton/redland-bindings/blob/dlang/dlang/source/rdf/raptor/uri.d
https://github.com/vporton/redland-bindings/blob/dlang/dlang/source/rdf/redland/uri.d

but as you see in this library there are two choices for URI 
class and it's unclear which of the two I would use.