Spec: Conversions: Specific rules apply to (non-constant) conversions between numeric types or to and from a string type. These conversions may change the representation of x and incur a run-time cost. All other conversions only change the type but not the representation of x. So converting to and from the underlying type of your custom … Read more
Unqualified lookup does not look in dependent base classes in class templates. So here: template <typename Socket> class StartSession : public Step<Session<Socket> > { protected: Session_ptr m_session; // <== unqualified name lookup on Session_ptr // … }; Step<Session<Socket>> is a dependent base class of StartSession<Socket>. In order to lookup there, you’ll have to do qualified … Read more
I think the key to understanding what is going on here is distinguishing between things that are determined dynamically at runtime, and things that are determined statically at compile time. It doesn’t help that, in most languages like Java, protocols (or interfaces) are all about getting polymorphic behavior at run time, whereas in Swift, protocols … Read more
Protocols with type aliases cannot be used this way. Swift doesn’t have a way to talk directly about meta-types like ValidationRule or Array. You can only deal with instantiations like ValidationRule where… or Array<String>. With typealiases, there’s no way to get there directly. So we have to get there indirectly with type erasure. Swift has … Read more