Confusion on Swift protocols and types

.playground

// example of confusion with swift protocols and classes

protocol Bar {
    var m: Int { get set }
}

class Foo:Bar {
    var m: Int
    
    required init(m: Int) {
        self.m = m
    }
}

class Baz: Bar {
    var m: Int
    
    required init(m: Int) {
        self.m = m
    }
}

class Cog: Foo {
    
     required init(m: Int) {
        super.init(m: m)
        self.m = m
    }
}

var t1 = Foo.self
println(t1)

var c1 = t1(m: 3)

println(c1)

// doesn't work: "Cannot assign a value of type Baz.Type to value of type Foo.Type"
t1 = Baz.self

// doesn't work: "Foo.Type does not conform to protocol Bar"
var t2: Bar = Foo.self