I use this all the time in C (specifically, C99 or later). I first saw it used in anger in `sokol_gfx`, and loved it. `FLECS` does something similar.

C makes it much better than C++ in that the designated initializes can be set in any order --- so I don't need to remember the often-arbitrary order of struct fields for the options struct.

I find it weird that C++ took this great C feature and kneecapped it ...