Cocoa® Programming

Appendix A. Unleashing the Objective-C Runtime

IN THIS APPENDIX

• Objective-C Objects

• Messaging with IMPs and Selectors

• Common Runtime Functions

• Forwarding, Distributed Objects, and Proxies

• Examples

Apple’s Objective-C runtime consists of a few key data structures and functions that implement Objective-C’s message sending semantics. This appendix describes Apple’s runtime, and most of the information here applies to the Gnu runtime. This appendix provides information about the implementation of Objective-C, which is not required to use the language. Most languages do not provide any programmer access to internal implementation details.

Directly manipulating the runtime enables many powerful uses of Objective-C including the integration of Objective-C ...