Make the PyArray::new method unsafe and document what can and cannot be done with its return value. #220
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…on-null pointers to the None object).
kngwyu
approved these changes
Nov 12, 2021
| for (i, item) in iter.enumerate() { | ||
| *array.uget_mut([i]) = item; | ||
| array.uget_raw([i]).write(item); |
…be done with its return value.
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Luckily, NumPy will always zero-initialize object pointers, c.f. https://github.com/numpy/numpy/blob/84e0707afa587e7655410561324ac36085db2b95/numpy/core/src/multiarray/ctors.c#L826-L835, so that even without invoking
Self::zeros, the return values ofSelf::newwill always be safe to drop.However their elements will be invalid (null pointers are not valid instances of
PyObjectasPy<...>is built onNonNull<...>). Hence the method is markedunsafeas referencing its elements will invoke undefined behaviour. To actually initialise the elements, the newuget_rawmethod is provided (and used internally infrom_iter,from_exact_iter,from_vec2andfrom_vec3where we currently invoke UB ourselves).Fixes #217