You just have to bring the ToString trait into scope, then the method is already implemented - so no need for unstable functionality.

But the reason that Encoding's use a function to compare encodings instead of comparing strings is twofold:

1. For performance, since it avoids an allocation (an possible re-allocations) inherent in creating the encoding string.
2. Just because two encodings don't have the same encoding doesn't mean they shouldn't "compare equal" (which you would see if you had kept the tests in parse.rs, e.g. "Vv" == Encoding::Void should pass).

• At least in the one place which this is really used, which is in objc, it is crucial that qualifiers are ignored, since otherwise the "verify_message" feature would basically be useless.