Comment by fuhsnn

There was a "__VA_TAIL__" WG14 proposal[1] that made it pretty simple to build custom map-like expansions, the OP's map example would be like:

> #define T(x, ...) printf(#x " = %d\n", x); __VA_TAIL__()

> T(1, 2, 3, 4, x, y, z)

You can play with it in the proposal author's ellipsis[2] and my slimcc[3], it's simple enough to implement (only about 30 lines of C) so I kept it in despite not seeing signs of it getting accepted.

[1] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3307.htm

[2] https://codeberg.org/gustedt/ellipsis

[3] https://github.com/fuhsnn/slimcc