Clonable.swift

/// Utility protocol for cloning objects.
public protocol Clonable {
}

public extension Clonable {
    
    /// Clones object with modifictation:
    ///
    /// Example:
    /// ```
    ///  let newUser = user.clone {
    ///    $0.name = "John"
    ///    $0.phone = "+1 978 873 88 19"
    ///  }
    /// ```
    ///
    /// - Parameter modificationBlock: modification applied to clonned object
    /// - Returns: new object with modified field
    func clone(with modificationBlock: ((inout Self) -> Void)? = nil) -> Self {
        var result = self
        modificationBlock?(&result)
        return result
    }
}