`protocol A: GenericProtocol where Instance == String { }` means, A is
something that `Instance` must be `String`.
However, it doesn't mean `Instance` has already been `String`.
So without assigning your `Instance`, the compiler doesn't know the type of
your `Instance`.
Zhao Xin
On Mon, Jun 26,
Hi,
I’m trying to implement something like this using Swift 4 after proposal 0142
is implemented:
```
protocol GenericProtocol {
associatedtype Instance
func foo() -> Instance
func bar() -> Instance
// and more...
}
protocol A: GenericProtocol where Instance == String { }
protoc
