fix MSVC compilation error in DEBUG mode due to free macro

[polyvertex]

Thanks for your library!

Using nanobind release 1.5.0, I faced the following compilation error with MSVC 2022 in DEBUG mode (_DEBUG defined) only due to macro free being defined as _free_dbg by Windows headers:

nb_func.cpp(94,20): error C2039: '_free_dbg': is not a member of 'nanobind::detail::func_data'

I am aware you wish to keep the project easily maintainable and this is a quick and least intrusive fix, however I am not yet familiar with nanobind so not sure it is the most ideal or correct approach.

Anyway here it is just in case :)

[wjakob]

This isn't a new issue, correct? I suppose that variable has been named free for a long time (since commit 765253b in Feb 2022). It was called free_capture before then. Can you rename it to that? (instead of freemem)

[polyvertex]

This isn't a new issue, correct?

If you refer to the definition of macro free by Windows headers, no it is not new. No pun intended :)

It was called free_capture before then. Can you rename it to that?

Done!

[wjakob]

With "new", I was referring to the nanobind version. I assume that the failure also occurs on v1.4.0?

[polyvertex]

With "new", I was referring to the nanobind version. I assume that the failure also occurs on v1.4.0?

I did not test, but a quick glance at the source of 1.4.0 shows that it certainly does yes. For the same reason indeed. I.e. struct func_data_prelim has a member named free, which name collides with the macro defined by Windows headers when _DEBUG is defined