Open Radar

 
Default implementations can be coded against the protocol, however, this still produces a bunch of potential copy/paste boiler plate for implementors of a protocol when dealing with properties. Extensions should be able to provide default implementations for those as well.

See Key Value Coding for a full example: http://owensd.io/2015/07/14/key-value-coding-in-swift.html

But basically, this code needs to be copied for every single implementor of KeyValueCodable:

struct Person : KeyValueCodable {
    var _kvcstore: Dictionary<String, Any> = [:]
}

In the general case, **every** implementation will use the exact same thing. This is bad for code maintenance and is just bad code duplication.

I would expect to be able to do this:

extension KeyValueCodable {
    var _kvcstore: Dictionary<String, Any> = [:]
}