Comment by s28l

I meant that they are processed before any syntactical analysis, so they're not particularly useful for this kind of thing. For example, these are all wrong usages of our hypothetical `#pragma unreachable`:

    void foo();
    #pragma unreachable
    class bar
    {
    #pragma unreachable
    };
    namespace foobar {
    #pragma unreachable
    }

But pragmas can generally be used anywhere, barring tokenization issues. The end result is that `pragma unreachable` would likely end up turning into a magic function call inside the compiler, since it really only makes sense in a spot where you can invoke a function.

Also, I think you are conflating pragmas with `__attribute__`, which is how you set per function optimization settings. If you do that with pragmas, then it isn't limited to a single function.