Swift protocol extension with initializer doesn't compile in extension of struct

Number:rdar://23376350 Date Originated:03-Nov-2015 09:49 AM
Status:Resolved Resolved:Xcode 9 beta 5
Product:Developer Tools Product Version:Swift 2.1
Classification:Other Bug Reproducible:Always

Protocols that define an initializer with an argument, that is then
declared in a protocol extension, and then implemented in the extension
of a struct, causes the program to not compile.

Steps to reproduce:

1. Create a protocol with an initializer
2. Implement the initializer in a protocol extension
3. Create an empty struct
4. Conform to the protocol in an extension on that struct
5. Call the initializer


1. Open the attached playground

Expected results:

Everything compiles correctly

Actual results:

A compiler error is produced:

'(string: String) -> Bar' is not convertible to '(string: String) -> Bar?'


- If you make the struct conform to the protocol in the definition ( not
  in an extension) it works



By keithbsmiley at Nov. 3, 2015, 5:50 p.m. (reply...)

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