Allow aliasing in ArrayView::from_shape #1410
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
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.
2 tasks
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
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
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
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