fix: only allow integer type_caster to call __int__ method when conversion is allowed; always call __index__ (#2698)
* Only allow integer type_caster to call __int__ or __index__ method when conversion is allowed
* Remove tests for __index__ as this seems to only be used to convert to int in 3.8+
* Take both `int` and `long` types into account for Python 2
* Add test_numpy_int_convert to assert tests currently fail, even though np.intc has an __index__ method
* Also consider __index__ as noconvert to a C++ integer
* New-style classes for Python 2.7; sigh
* Add some tests on types with custom __index__ method
* Ignore some tests in Python <3.8
* Update comment about conversion from np.float32 to C++ int
* Workaround difference between CPython and PyPy's different PyIndex_Check (unnoticed because we currently don't have PyPy >= 3.8)
* Avoid ICC segfault with py::arg()
3 files changed
