objc:retain

(objc:retain pointer)

Sends retain and answers pointer. The reference is the program's to release: a pointer value's collector does not release an explicit retain, which is how a program keeps an object alive after dropping its pointer. Part of the macOS-only objc package -- the interpreter (java -jar, or the rontolisp native binary), a compiled .class / .jar and a --native executable for macOS on Apple silicon, never a .wasm; on a machine without the runtime it signals an error. See the macOS GUI guide.

CL-USER> (defvar *o* (objc:alloc-init-object "NSObject"))
*O*
CL-USER> (objc:retain-count (objc:retain *o*))
2