IGNITE-15266 Add isclass check to is_hinted

[bojidar-bg]

The issue seems to be caused by issubclass requiring its first parameter to be a class, which isn't the case for two-element tuples like the ones used by e.g. object arrays for hinting the object array type ((-1, [...])). Hence, an obvious patch would be to just double check that we are using it with a class.

Performance impact:

$ python -m timeit -r 25 -s "from inspect import isclass; a = int;" -- "isclass(a)"
2000000 loops, best of 25: 133 nsec per loop
$ python -m timeit -r 25 -s "from inspect import isclass; a = int;" -- "isclass(a) and issubclass(a, float)"
1000000 loops, best of 25: 236 nsec per loop
$ python -m timeit -r 25 -s "from inspect import isclass; a = [];" -- "isclass(a) and issubclass(a, float)"
2000000 loops, best of 25: 158 nsec per loop
$ python -m timeit -r 25 -s "a = int;" -- "try:" "  issubclass(a, float)" "except:" "  pass"
2000000 loops, best of 25: 114 nsec per loop
$ python -m timeit -r 25 -s "a = [];" -- "try:" "  issubclass(a, float)" "except:" "  pass"
1000000 loops, best of 25: 333 nsec per loop

Doesn't seem to impactful to me, we can do a million of those in a millisecond.

[ivandasch]

@bojidar-bg Great catch, Bojidar. Could you please add a test case for it? I've really appreciate your effort and create some tests for your case, please add tests to your patch. Also, we have already imported inspect here, please use inspect.isclass.
Or you can just use my patch. Apply it and commit to your branch. After it, I will merge you PR. Thank you!

Also I'd suggest not to use OBJECT_ARRAY at all, Ignite itself doesn't have a great support of it. Use Collections (simple list) instead.
Add_tests_to_patch.txt

[bojidar-bg]

Ah, good spot, didn't notice it was already imported! Thanks for the patch, just went ahead and used it ☺

[ivandasch]

@bojidar-bg Great, I'll merge a fix today. I cannot give your a promise to release 0.5.2 as ASAP, unfortunatelly. But let's wait for a while, may be others bugs appears, so we can ship a new bugfix release.