> The only correct ways to verify that a variable contains either a valid numeric string or integer is by comparing type, and then using a regex or a double string-then-int cast.

You know there is an entire extension dedicated to validating and sanitising inputs right?

All your type checking and regexes and double cast comparisons could be replaced with:

    if (($value = filter_var($value, FILTER_VALIDATE_INT)) !== false) { doStuff(); }

> You could try to blame PHP, but really it's the developers

At least we can agree on one thing.