rust/library/alloc/src/vec/drain.rs, branch perf-tmp

rename sub_ptr 😅

2025-02-23T16:11:00+00:00

Reformat `use` declarations.

2024-07-28T22:26:52+00:00

The previous commit updated `rustfmt.toml` appropriately. This commit is the outcome of running `x fmt --all` with the new formatting options.

enable `rust_2018_idioms` for doctests

2023-05-06T21:12:29+00:00

Signed-off-by: ozkanonur

Rollup merge of #110635 - scottmcm:zst-checks, r=the8472

2023-04-22T01:33:57+00:00

More `IS_ZST` in `library` I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways https://github.com/rust-lang/rust/blob/d19b64fb54391b64ce99981577c67c93ac2a9ffa/library/core/src/slice/iter/macros.rs#L76-L93 so started making this PR, then added a few more I found since I was already making changes anyway.

More `IS_ZST` in `library`

2023-04-21T23:29:27+00:00

I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways https://github.com/rust-lang/rust/blob/d19b64fb54391b64ce99981577c67c93ac2a9ffa/library/core/src/slice/iter/macros.rs#L76-L93 so started making this PR, then added a few more I found since I was already making changes anyway.

More `mem::take` in `library`

2023-04-21T02:54:46+00:00

A bunch of places were using `replace(…, &mut [])`, but that can just be `take`.

Don't do pointer arithmetic on pointers to deallocated memory

2023-01-17T21:01:33+00:00

vec::Splice can invalidate the slice::Iter inside vec::Drain. So we replace them with dangling pointers which, unlike ones to deallocated memory, are allowed.

Make ZST checks in core/alloc more readable

2022-09-23T06:12:29+00:00

There's a bunch of these checks because of special handing for ZSTs in various unsafe implementations of stuff. This lets them be `T::IS_ZST` instead of `mem::size_of::() == 0` every time, making them both more readable and more terse. *Not* proposed for stabilization at this time. Would be `pub(crate)` except `alloc` wants to use it too. (And while it doesn't matter now, if we ever get something like 85836 making it a const can help codegen be simpler.)

fill-in tracking issue for `feature(drain_keep_rest)`

2022-08-28T13:02:37+00:00

add examples to `vec::Drain{,Filter}::keep_rest` docs

2022-08-28T12:58:06+00:00