swiftlang/swift

[SR-1283] RawRepresentable extension for Self:NSCoding breaks implicit RawRepresentable implementation for enums

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#43,891 opened on Apr 21, 2016

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 (2 comments) (0 reactions) (0 assignees)Swift (10,719 forks)batch import
bugcompilergood first issue

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Description
Previous ID SR-1283
Radar None
Original Reporter josh (JIRA User)
Type Bug

Apple Swift version 2.2 (swiftlang-703.0.18.1 clang-703.0.29)
Votes 0
Component/s Compiler
Labels Bug, StarterBug
Assignee None
Priority Medium

md5: ebcb1594c186768ea99ccc914c314b25

Issue Description:

Copy + paste attached sample code into a Playground.

import Foundation

enum Status: Int {
    case Good
    case Bad
}

extension RawRepresentable where Self: NSCoding {
    init?(rawValue: NSData) {
        if let instance = NSKeyedUnarchiver.unarchiveObjectWithData(rawValue) as? Self {
            self = instance
        } else {
            return nil
        }
    }
    
    var rawValue: NSData {
        get {
            return NSKeyedArchiver.archivedDataWithRootObject(self)
        }
    }
}

Contributor guide

Research direction
Investigate the conflicting RawRepresentable extension and determine how to resolve the ambiguity.
Tech stack
swift
Domain
compilers
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Swift
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75