[londons_explore]

But only if you have a lot of message formats...

Generally, message specifications are written by hand, so even a big project may only have a couple of hundred. Doesn't sound so bad.

Also, presumably, if code size really is a big concern, you can decode this in more code efficient ways too, as long as you are less concerned with performance.

[quotemstr]

You might be surprised to see how quickly mechanically-generated marshaling code adds up. Look at Android's frameworks.jar one day and see how much is just the same AIDL-generated Parcel-manipulation code over and over again. Cache effects and IO costs are so severe in modern computing that my default (but rebuttable!) position is to prefer table-driven approaches over code generation wherever possible.

Windows COM switched from codegen to table-driven "stubless" marshaling decades ago at no noticeable cost to performance and with a huge code size win.