doc: change take index out of range access to be undefined behavior and not guarantee panic#9278
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rluvaton wants to merge 1 commit intoapache:mainfrom
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doc: change take index out of range access to be undefined behavior and not guarantee panic#9278rluvaton wants to merge 1 commit intoapache:mainfrom
rluvaton wants to merge 1 commit intoapache:mainfrom
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I want to add some optimizations that uses `get_unchecked` but the safety comment says that we panic on out of range access which might not be the case for `get_unchecked`
Dandandan
reviewed
Jan 27, 2026
| /// # Safety | ||
| /// | ||
| /// When `options` is not set to check bounds, taking indexes after `len` will panic. | ||
| /// When `options` is not set to check bounds, taking indexes after `len` is *undefined behavior*. |
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We can't just document that something is UB (we would need to mark the code as unsafe as well and need to assure we never pass OOB indices).
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Maybe we need to add a fn unsafe take_unchecked 🤔
alamb
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Jan 28, 2026
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alamb
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Agree with @Dandandan here
| /// # Safety | ||
| /// | ||
| /// When `options` is not set to check bounds, taking indexes after `len` will panic. | ||
| /// When `options` is not set to check bounds, taking indexes after `len` is *undefined behavior*. |
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Maybe we need to add a fn unsafe take_unchecked 🤔
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|
Yes I also agree |
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Which issue does this PR close?
None
Rationale for this change
I want to add some optimizations that uses
get_uncheckedbut the safety comment says that we panic on out of range access which might not be the case forget_unchecked.for example this pr:
What changes are included in this PR?
Update safety note
Are these changes tested?
No
Are there any user-facing changes?
Yes, we no longer guarantee that out of range will panic and instead it can lead to undefined behavior, which the user might not be able to catch