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Improve the example for ptr::copy - #77385
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rust-highfive
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Oct 1, 2020
r? @KodrAus (rust_highfive has picked a reviewer for you, use r? to override) |
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jyn514
commented
Oct 1, 2020
@bors r+ rollup |
bors
commented
Oct 1, 2020
📌 Commit e58f3d3 has been approved by |
| /// | ||
| /// /// # Safety: | ||
| /// /// * `ptr` must be correctly aligned for its type and non-zero. | ||
| /// /// * `ptr` must be valid for reads of `elts` contiguous objects of type `T`. |
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I never heard of "contiguous objects"? Is this perhaps a new term? Also, s/of/for.
| /// /// * `ptr` must be valid for reads of `elts` contiguous objects of type `T`. | |
| /// /// * `ptr` must be valid for reads of `elts` contiguous objects for type `T`. |
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Try ctrl+f 'contiguous' on https://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#guarantees
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Yes, contiguous is there but I never heard of contiguous objects. Try rg 'contiguous objects' in rust or https://github.com/rust-lang/rust/search?q=%22contiguous+objects%22
| /// /// # Safety: | ||
| /// /// * `ptr` must be correctly aligned for its type and non-zero. | ||
| /// /// * `ptr` must be valid for reads of `elts` contiguous objects of type `T`. | ||
| /// /// * Those elements must not be used after calling this function unless `T: Copy`. |
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Is this required? Is it only limited for Copy?
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Yes, if these are not Copy you'll have a double-free. ptr::read does not drop or move the source buffer.
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Okay, I guess that's true but should this be part of safety? I think it could be but I wonder if this should be here.
| /// ``` | ||
| /// use std::ptr; | ||
| /// | ||
| /// /// # Safety: |
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| /// /// # Safety: | |
| /// /// # Safety | |
| /// /// |
We usually have a space after Safety for heading and don't have : at the end.
Improve the example for ptr::copy Fixesrust-lang#77220
Rollup of 11 pull requests Successful merges: - rust-lang#76851 (Fix 'FIXME' about using NonZeroU32 instead of u32.) - rust-lang#76979 (Improve std::sys::windows::compat) - rust-lang#77111 (Stabilize slice_ptr_range.) - rust-lang#77147 (Split sys_common::Mutex in StaticMutex and MovableMutex.) - rust-lang#77312 (Remove outdated line from `publish_toolstate` hook) - rust-lang#77362 (Fix is_absolute on WASI) - rust-lang#77375 (rustc_metadata: Do not forget to encode inherent impls for foreign types) - rust-lang#77385 (Improve the example for ptr::copy) - rust-lang#77389 (Fix some clippy lints) - rust-lang#77399 (BTreeMap: use Unique::from to avoid a cast where type information exists) - rust-lang#77429 (Link `new` method in `DefautHasher`s doc) Failed merges: r? `@ghost`
Fixes#77220