nope it doesn't..

```ruby
irb(main):001:0> "0x2341".to_f
=> 0.0
irb(main):002:0> "01234".to_f
=> 1234.0
```
so the old is_numeric and is_integer only worked for strings with decimal integers/floats (and why I started this pull request: it crashes if you try to validate a hash or array which should only return false instead of throwing an exception)

also not sure if something like 1234.2341e-12 was handled before.. I think only exceptionally.. if the format ruby is showing with .to_s was the same like the input.. so maybe we shouldn't handle them as well?