Ambiguous inits

inits.swift

struct Foo {
    init(a: String) {
        print("init(a: String)")
    }
    
    init(b: String) {
        print("init(b: String)")
    }
    
    init(a: Int) {
        print("init(a: Int)")
    }
    
    init<T>(a: T) {
        print("init<T>(a: T)")
    }
    
    init<T>(_ a: T) {
        print("init<T>(_ a: T)")
    }
    
}

let numbers = [1, 2, 3]
let strings = ["1", "2", "3"]

let w = numbers.map(Foo.init)
let x = w.map(Foo.init)         // error here, no init optimized for Foo

let y = strings.map(Foo.init)   // error here, two inits optimized for String