Namespaces Extends?

Hate to bring this one up; I'll be brief! for instance smarty get's upgraded and has it's own namespace, I have a class which extends it, soon to be in my applications namespace which implements an interface in my interfaces namespace.. how does one extend a class in another namespace and indeed implement? namespace application::handlers; { class class_name extends ::b::class_in_other_namespace implements ::c::iTemplate{ public func... } } or would we.. namespace application::handlers; { use b::class_in_other_namespace as other_class; use c::interface_in_other_namespace as other_interface; class class_name extends other_class implements other_interface { public func... } } or..? Thanks!