Function send_message 

pub unsafe fn send_message<R>(obj: *const c_void, sel: Sel) -> R

Helper function to send a message with the given selector.

This is the Rust equivalent of C++’s Object::sendMessage<>.

Safety

• obj must be a valid Objective-C object pointer
• sel must be a valid selector for the object
• The return type must match the actual return type of the method