Avoid `goto`

Reason

Readability, avoidance of errors. There are better control structures for humans; goto is for machine generated code.

Exception

Breaking out of a nested loop. In that case, always jump forwards.

for (int i = 0; i < imax; ++i)
    for (int j = 0; j < jmax; ++j) {
        if (a[i][j] > elem_max) goto finished;
        // ...
    }
finished:
// ...

Example, bad

There is a fair amount of use of the C goto-exit idiom:

void f()
{
    // ...
        goto exit;
    // ...
        goto exit;
    // ...
exit:
    // ... common cleanup code ...
}

This is an ad-hoc simulation of destructors. Declare your resources with handles with destructors that clean up. If for some reason you cannot handle all cleanup with destructors for the variables used, consider gsl::finally() as a cleaner and more reliable alternative to goto exit

Enforcement

• Flag goto. Better still flag all gotos that do not jump from a nested loop to the statement immediately after a nest of loops.