Open Radar

 
Summary:
Mistakingly implementing a protocol using a generic implementation rather than the protocol parameter specified in the protocol causes a segfault 11 error. This scenario is common since generic protocol parameters aren't supported in some scenarios. The solution is to change from the generic version of the function/method and explicitly label the parameter type to the protocol itself

Steps to Reproduce:
Attempt to compile this snippet into Xcode:

protocol Thing {
    var name: String { get }
}
 
protocol UsingThing {
    func doSomething(with: Thing)
}
 
struct Test: UsingThing {
    func doSomething<T: Thing>(thing: T) {
        
    }
}

Expected Results:
Expected this compile to fail with an error message telling me the implementation of the function in the struct is specified incorrectly, and should point me to the protocol for reference

Actual Results:
Segfault 11
See attached Xcode Playground crashlog

Version:
Xcode 6.4 (6E35b)
OS X 10.10.4

Notes:
Workaround: Find all instances of improper use of method and correct usage.

Configuration:
Xcode Playground

Attachments:
'com.apple.dt.Xcode.Playground_2015-07-09-131337_honolulu.crash' was successfully uploaded.