[swift-users] Vague error description when trying to match an instance in a switch statement

hello at jtorhoff.com hello at jtorhoff.com
Thu Sep 15 13:53:07 CDT 2016

The following code

struct A {}

let x = A()
let y = A()

switch x {
     case y:

produces "error: expression pattern of type 'A' cannot match values of 
type 'A'".
This is kind of a vague description of what is really going on,
the compiler actually expects A to adopt Equatable protocol.

I'm using:
Apple Swift version 3.0 (swiftlang-800.0.46.2 clang-800.0.38)
Target: x86_64-apple-macosx10.9

I wasn't sure where to post this.
It would be nice if the error message could be improved to spare 
confusion for
the other developers.

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