#include 
    int main(int argc, char **argv) {
        if (argc != 2) {
            fprintf(stderr, "usage: require one numeric argument");
        }
        char *nump = argv[1];
        unsigned neg = 0;
        unsigned long long ures = 0;
        if (*nump == '-') {
            neg = 1;
            nump = nump + 1;
        }
        if (!*nump) {
            fprintf(stderr, "require non empty string\n");
            return 1;
        }
        char b;
        while (b = *nump++) {
            if (b >= '0' && b <= '9') {
                unsigned long long nres = (ures * 10) + (b - '0'); 
                if (nres < ures) {
                    fprintf(stderr, "overflow in '%s'\n", argv[1]);
                    return 1;
                }   
                ures = nres;
            } else {
                if (b >= ' ') {
                    fprintf(stderr, "invalid char '%c' in '%s'\n", b, argv[1]); 
                } else {
                    fprintf(stderr, "invalid byte '%d' in '%s'\n", b, argv[1]);
                }
                return 1;  
            }
        }
        long long res = (long long) ures;
        if (neg) {
            if (ures <= 0x8000000000000000ULL) {
                res = -res;
            } else {
                fprintf(stderr, "underflow in '%s'\n", argv[1]);
                return 1;
            }
        } else if (ures > 0x7FFFFFFFFFFFFFFFULL) {
            fprintf(stderr, "overflow in '%s'\n", argv[1]);
            return 1;
        }
        fprintf(stdout, "result: %lld\n", res);
        return 0;
    }

    unsigned foo(unsigned a, unsigned b) { return a - b; }

    unsigned foo(unsigned a, unsigned b) {
      auto c = a - b;
      return c >= 0 ? c : 0;
    }

Personally, I find waiting more than 200ms unacceptable and really < 50ms is ideal. When the feedback is very small, it becomes practical to save the file on every keystroke and get nearly instantaneous results with every input char.

What if the old timers were actually right? I tend to think they were.

You can only speak for yourself.

I also dislike RAII because it often makes it difficult to reason about when destructors are run and also admits accidental leaks just like defer does. Instead what I would want is essentially a linear type system in the compiler that allows one to annotate data structures that require cleanup and errors if any possible branches fail to execute the cleanup. This has the benefit of making cleanup explicit while also guaranteeing that it happens.

I disagree. The code you wrote is a collaboration with the model you used. To frame it this way, you are taking credit for the work the model did on your behalf. There is a difference between I wrote this code entirely by myself and I wrote the code with a partner. For me, it is analogous to the author of the score of an opera taking credit for the libretto because they gave the libretto author the rough narrative arc. If you didn't do it yourself, it isn't yours.

I generally prefer integrated works or at least ones that clearly acknowledge the collaboration and give proper credit.