Comment by kaba0

C's macros are primitive and unsafe but by no means useless. Here's a somewhat silly example from embedded programming. I wanted to embed the bitmaps of a small set of characters for use on a bitmapped monochrome display. It was easy to define macros CHAR_GRID, _ and X such that e.g.

    const uint8_t zero[] = {
      CHAR_GRID(
        _,X,X,X,_,
        X,_,_,_,X,
        X,_,_,X,X,
        X,_,X,_,X,
        X,X,_,_,X,
        X,_,_,_,X,
        _,X,X,X,_
      )
    };

desugared to a column-major array of 5 bytes.

    #define CHAR_GRID(c1r1, c2r1, c3r1, c4r1, c5r1, \
    c1r2, c2r2, c3r2, c4r2, c5r2, c1r3, c2r3, c3r3, c4r3, c5r3, c1r4, c2r4, c3r4, c4r4, c5r4, c1r5, c2r5, c3r5, c4r5, c5r5, c1r6, c2r6, c3r6, c4r6, c5r6, c1r7, c2r7, c3r7, c4r7, c5r7) \
 c1r1 | (c1r2 << 1) | (c1r3 << 2) | (c1r4 << 3) | (c1r5 << 4) | (c1r6 << 5) | (c1r7 << 6), \
 c2r1 | (c2r2 << 1) | (c2r3 << 2) | (c2r4 << 3) | (c2r5 << 4) | (c2r6 << 5) | (c2r7 << 6), \
 c3r1 | (c3r2 << 1) | (c3r3 << 2) | (c3r4 << 3) | (c3r5 << 4) | (c3r6 << 5) | (c3r7 << 6), \
 c4r1 | (c4r2 << 1) | (c4r3 << 2) | (c4r4 << 3) | (c4r5 << 4) | (c4r6 << 5) | (c4r7 << 6), \
 c5r1 | (c5r2 << 1) | (c5r3 << 2) | (c5r4 << 3) | (c5r5 << 4) | (c5r6 << 5) | (c5r7 << 6)

Something like the Flecs ECS (https://www.flecs.dev/flecs/) which makes Rust's Bevy team jealous makes extensive use of C's "useless macros".

While that’s true, preprocessors are pretty trivial to write these days if you want macros that the language doesn’t support. Racket excels at this.