Default output validation fails for inf and nan answer

[RagnarGrootKoerkamp]

Admittedly this is rather pedantic, so feel free to just close, but in case you are interested:

I just added some tests to the BAPCtools default output validator to handle inf, -inf, and nan as possible answers to testcases in the presence of float_tolerance 0.5.

Some cases that problemtools currently fails to handle:

answer	output	expected	actual
inf	inf	ac	wa
inf	INF	ac	wa
inf	-inf	wa	ac
inf	0	wa	ac
-inf	-1	wa	ac
nan	nan	ac	wa
nan	NaN	ac	wa

(You could argue what relative error means in the context of infinite values, but some of these are clearly wrong.)

To run some tests, clone the BAPCtools repository and change line 50 to:

validator = validate.OutputValidator(p, Path('/path/to/problemtools/support/default_validator/default_validator.cc'))

and run pytest -k default_output from the repository root.

CC @ludopulles who found this