The protobuf source code includes examples in C++, go, and Python, while Google has guides for C++, C#, Go, Java, and Python. Protobuf includes support for Objective-C, and Apple has a plugin for Swift—but there aren't examples or guides for either language.
This is a simple port of the C++ examples to Swift and Objective-C.
Currently the examples are only for protobuf version 2. I plan to update these to version 3. Soon. In my copious free time.
There is a Makefile that builds the C++ and Objective-C examples. The runtime component is build from the protobuf source code, which is included as a submodule.
There is also an Xcode project, objc.xcodeproj, that has targets for add_person and list_people.
I haven't cracked a simple build formula for Swift so that it can be build from the Makefile. There is a swift.xcodeproj that has targets for add_person and list_people.
Note: I'd love to be able to build this from the command line in a similar way as I do the Objective-C examples. That is, without using the swift package manager and associated files and directories. If anyone has pointers on this, I'd love to hear them.