// RUN: %target-swift-frontend -primary-file %s -emit-ir

public func ==<T: EquatableMetaType>(lhs: T, rhs: T) -> Bool {
    return type(of: lhs) == type(of: lhs)
}


public protocol EquatableMetaType {
}


class Block : Equatable, EquatableMetaType {
}

extension Array where Element : Block {
    func indexByType(of: Element) -> Array.Index? {
        let count = self.count
        var result: Array.Index = 0
        
        for i in self {
            if i == of {
                return result
            }
            if result < count {
                result += 1
            }
        }
        return nil
    }
}