[Rendello]

My favourite variation is from Zig:

    const hello_world_in_c =
        \\#include <stdio.h>
        \\
        \\int main(int argc, char **argv) {
        \\    printf("hello world\n");
        \\    return 0;
        \\}
    ;

It neatly sidesteps the whole "cat-and-mouse" issue.

Pair this with the fact that it only has the C++ style // comments, it means that every line can be tokenized independently. Not that that particularly matters for programmers, but I know Vim sometimes gets confused about where Python's strings end and it turns the syntax highlighting to garbage.

[afiori]

it also fixes the indentation problem