Why can't I initialize this struct?

Question

I want to make a Swift Error that describes how the Type of a variable coming from Objective-C was wrong. Here's how I tried to define the struct:

public struct UnexpectedResultTypeError<Expected, Actual>: Error {
    let expected: Expected.Type
    let actual: Actual.Type

    init(expected: Expected.Type, got actual: Actual.Type) {
        self.expected = expected
        self.actual = actual
    }
}

I figured that was fine, but now I can't initialize it:

UnexpectedResultTypeError<String, Any>(expected: String.self, got: type(of: serializedResult))

Cannot invoke initializer for type 'UnexpectedResultTypeError<String, Any>' with an argument list of type '(expected: String.Type, got: Any.Type)'