Swift typealias problem

typealias.swift

protocol SomeProtocol {
    typealias SomeType = String
}

class SomeClass: SomeProtocol {
    let something: SomeType
}

// Compiles in Swift 3.1
// Compile error in Swift 3.0.2: "Use of undeclared type SomeType"

// The same problem exists with associated types:

protocol HasAssociatedType {
    associatedtype CustomType
    
    var something: CustomType { get }
}

class ImplementsAssociatedType: HasAssociatedType {
    var something: String? // infers CustomType = String?
    
    var somethingElse: CustomType { // Error: "Use of undeclared type CustomType"
        return something
    }
}