Box validity: update for new zero-sized rules #129748
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library/alloc/src/boxed.rs
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| //! [`ptr::NonNull::dangling`]. Even for zero-sized types, the pointee type must be inhabited | ||
| //! to ensure that the Box points to a valid value of the given type. |
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Can we retain an example of what makes something "uninhabited" in this case, or a link to documentation that describes the notion of something being uninhabited?
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I struggled a bit with what to say here and would welcome suggestions.
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A quick grep indicates this is the first time we're using the word in the standard library documentation. But the reference: https://github.com/rust-lang/reference/blob/master/src/glossary.md?plain=1#L284-L289 and the dev guide: https://github.com/rust-lang/rustc-dev-guide/blob/master/src/appendix/glossary.md?plain=1#L93 both provide a definition.
If we need to put a definition in the standard library docs I'm not sure where it would go, but I'd be happy pasting either of these in. Or just directing people to the reference, though that sounds bit-rotty unless we have something that checks that a link to that specific glossary entry still works.
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Since I don't think (un)inhabited types should be special-cased here, I have chosen an entirely different wording now.
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Yeah, this looks correct. @bors r+ rollup |
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…iaskrgr Rollup of 12 pull requests Successful merges: - rust-lang#129748 (Box validity: update for new zero-sized rules) - rust-lang#129829 (Make decoding non-optional `LazyArray` panic if not set) - rust-lang#129856 (compiler_fence documentation: emphasize synchronization, not reordering) - rust-lang#129868 (Remove kobzol vacation status) - rust-lang#129875 (chore: Fix typos in 'compiler' (batch 1)) - rust-lang#129877 (chore: Fix typos in 'compiler' (batch 2)) - rust-lang#129878 (chore: Fix typos in 'compiler' (batch 3)) - rust-lang#129890 (Remove stray word in a comment) - rust-lang#129892 (Clarify language around ptrs in slice::raw) - rust-lang#129905 (mailmap: add new email for davidtwco) - rust-lang#129906 (mailmapper?) - rust-lang#129907 (Fix compile error in solid's remove_dir_all) r? `@ghost` `@rustbot` modify labels: rollup
Rollup merge of rust-lang#129748 - RalfJung:box-validity, r=workingjubilee Box validity: update for new zero-sized rules Fixes rust-lang/unsafe-code-guidelines#529 Cc `@joshlf` `@rust-lang/opsem`
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@rustbot label A-box |
Fixes rust-lang/unsafe-code-guidelines#529
Cc @joshlf @rust-lang/opsem