Vendor things

third-party/vendor/objc2/examples/introspection.rs

@@ -0,0 +1,58 @@
+use objc2::foundation::NSObject;
+use objc2::runtime::Class;
+use objc2::{sel, ClassType, Encode};
+
+fn main() {
+    // Get the class representing `NSObject`
+    let cls = NSObject::class();
+
+    // Inspect various properties of the class
+    println!("NSObject superclass: {:?}", cls.superclass());
+    println!("NSObject size: {}", cls.instance_size());
+    println!(
+        "-[NSObject alloc] would work: {}",
+        cls.responds_to(sel!(alloc))
+    );
+    println!(
+        "+[NSObject alloc] would work: {}",
+        cls.metaclass().responds_to(sel!(alloc))
+    );
+
+    // Inspect an instance variable on the class
+    //
+    // Note: You should not rely on the `isa` ivar being available,
+    // this is only for demonstration.
+    let ivar = cls
+        .instance_variable("isa")
+        .expect("No ivar with name 'isa' found on NSObject");
+    println!(
+        "Instance variable {} has type encoding {:?}",
+        ivar.name(),
+        ivar.type_encoding()
+    );
+    assert!(<*const Class>::ENCODING.equivalent_to_str(ivar.type_encoding()));
+
+    // Inspect a method of the class
+    let method = cls.instance_method(sel!(hash)).unwrap();
+    println!(
+        "-[NSObject hash] takes {} parameters",
+        method.arguments_count()
+    );
+    #[cfg(feature = "malloc")]
+    {
+        let hash_return = method.return_type();
+        println!("-[NSObject hash] return type: {:?}", hash_return);
+        assert!(usize::ENCODING.equivalent_to_str(&hash_return));
+    }
+
+    // Create an instance
+    let obj = NSObject::new();
+
+    println!("NSObject address: {:p}", obj);
+
+    // Access an ivar of the object
+    //
+    // As before, you should not rely on the `isa` ivar being available!
+    let isa = unsafe { *obj.ivar::<*const Class>("isa") };
+    println!("NSObject isa: {:?}", isa);
+}