Add separate macro for msg_send! that does not verify message types

[faern]

The verify_message feature is awesome! Sadly when you enable it all messages must pass the verification. This also adds the requirement that all messages implement Encode. I have a case where I want the message types verified for me at compile time, but a few msg_send! calls include types that do not implement Encode, as a result I must opt out of all message verification.

I can manually verify messages. But that is cumbersome, and eventually a developer will forget to do it, skipping the safety checks.

Can we add a separate msg_send_unverified! that is always identical to what msg_send! does when verify_message is disabled?

[madsmtm]

I'd argue no, for several reasons:

• Ideally, the macro should always take Encode types, since it helps a lot against passing types that are not valid C types (e.g. accidentally passing Vec<u8> or &str).
• The message sending ABI arguably requires it, e.g. the current way of doing it with comparing type IDs doesn't allow otherwise valid newtypes.
• It can be really nice for the verification to automatically be enabled when debug_assertions are, instead of requiring the user to manually enable the feature.

(I've made all of these changes in my fork objc2, so a bit of my argument is also from there, might not apply directly here).

Instead, when calling methods with arguments that don't implement Encode, you should either:

• Implement Encode for the type (or a #[repr(transparent)] wrapper type).
• Convert it to an equivalent type that does implement Encode.

[madsmtm]

(In your case, that would be implementing Encode for NSOperatingSystemVersion)

[faern]

You are completely right! This was an oversight from me. I did a quick code cleanup and did not realize NSOperatingSystemVersion was our own struct. I did not realize we could implement Encode for it ourselves. Well then, problem solved :) Thank you for the input