Allow aliasing in ArrayView::from_shape #1410
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Changes the checks in the ArrayView::from_shape constructor so that it allows a few more cases: custom strides that lead to overlapping are allowed. Before, both ArrayViewMut and ArrayView applied the same check, that the dimensions and strides must be such that no elements can be reached by more than one index. However, this rule only applies for mutable data, for ArrayView we can allow this kind of aliasing. This is in fact how broadcasting works, where we use strides to repeat the same array data multiple times.
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bluss
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Aug 3, 2024
It should deny overlapping indexes. Because it's an unsafe function and we only do these checks on best-effort basis (caller has to ensure they are correct), it's a debug assertion. Removed the small addition to a doc comment that was done in a previous PR (it was an unfinished idea). Similar to pr #1410 Finishes and closes #919
bluss
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Aug 3, 2024
It should deny overlapping indexes. Because it's an unsafe function and we only do these checks on best-effort basis (caller has to ensure they are correct), it's a debug assertion. Removed the small addition to a doc comment that was done in a previous PR (it was an unfinished idea). Similar to pr #1410 Finishes and closes #919
bluss
added a commit
that referenced
this pull request
Aug 3, 2024
It should deny overlapping indexes. Because it's an unsafe function and we only do these checks on best-effort basis (caller has to ensure they are correct), it's a debug assertion. Removed the small addition to a doc comment that was done in a previous PR (it was an unfinished idea). Similar to pr #1410 Finishes and closes #919
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Changes the checks in the ArrayView::from_shape constructor so that it allows a few more cases: custom strides that lead to overlapping are allowed.
Before, both ArrayViewMut and ArrayView applied the same check, that the dimensions and strides must be such that no elements can be reached by more than one index.
However, this rule only applies for mutable data, for ArrayView we can allow this kind of aliasing. This is in fact how broadcasting works, where we use strides to repeat the same array data multiple times.
Fixes the second point in #919