rust/src/liballoc/boxed.rs, branch try

mv std libs to library/

2020-07-28T00:51:13+00:00

Remove the usage of the LengthAtMost32 trait

2020-07-05T12:47:08+00:00

Rollup merge of #73678 - Keno:patch-1, r=LukasKalbertodt

2020-07-01T14:42:42+00:00

Update Box::from_raw example to generalize better I know very little about rust, so I saw the example here ``` use std::alloc::{alloc, Layout}; unsafe { let ptr = alloc(Layout::new::()) as *mut i32; *ptr = 5; let x = Box::from_raw(ptr); } ``` and tried to generalize it by writing, ``` let layout = Layout::new::(); let new_obj = unsafe { let ptr = alloc(layout) as *mut T; *ptr = obj; Box::from_raw(ptr) }; ``` for some more complicated `T`, which ended up crashing with SIGSEGV, because it tried to `drop_in_place` the previous object in `ptr` which is of course garbage. I think that changing this example to use `.write` instead would be a good idea to suggest the correct generalization. It is also more consistent with other documentation items in this file, which use `.write`. I also added a comment to explain it, but I'm not too attached to that, and can see it being too verbose in this place.

lints: add `improper_ctypes_definitions`

2020-06-24T11:09:35+00:00

This commit adds a new lint - `improper_ctypes_definitions` - which functions identically to `improper_ctypes`, but on `extern "C" fn` definitions (as opposed to `improper_ctypes`'s `extern "C" {}` declarations). Signed-off-by: David Wood

Update Box::from_raw example to generalize better

2020-06-24T02:42:35+00:00

I know very little about rust, so I saw this example and tried to generalize it by writing, ``` let layout = Layout::new::(); let new_obj = unsafe { let ptr = alloc(layout) as *mut T; *ptr = obj; Box::from_raw(ptr) }; ``` for some more complicated `T`, which ended up crashing with SIGSEGV, because it tried to `drop_in_place` the previous object in `ptr` which is of course garbage. I also added a comment that explains why `.write` is used, but I think adding that comment is optional and may be too verbose here. I do however think that changing this example is a good idea to suggest the correct generalization. `.write` is also used in most of the rest of the documentation here, even if the example is `i32`, so it would additionally be more consistent.

Rollup merge of #72709 - LeSeulArtichaut:unsafe-liballoc, r=nikomatsakis

2020-06-19T16:14:58+00:00

`#[deny(unsafe_op_in_unsafe_fn)]` in liballoc This PR proposes to make use of the new `unsafe_op_in_unsafe_fn` lint, i.e. no longer consider the body of an unsafe function as an unsafe block and require explicit unsafe block to perform unsafe operations. This has been first (partly) suggested by @Mark-Simulacrum in https://github.com/rust-lang/rust/pull/69245#issuecomment-587817065 Tracking issue for the feature: #71668. ~~Blocked on #71862.~~ r? @Mark-Simulacrum cc @nikomatsakis can you confirm that those changes are desirable? Should I restrict it to only BTree for the moment?

`#[deny(unsafe_op_in_unsafe_fn)]` in liballoc

2020-06-19T11:47:01+00:00

Reduce pointer casts in Box::into_boxed_slice

2020-06-17T23:30:27+00:00

We only need to cast the pointer once to change `Box` to an array `Box<[T; 1]>`, then we can let unsized coercion return `Box<[T]>`.

Rollup merge of #72499 - mendess:master, r=dtolnay

2020-05-30T11:45:06+00:00

Override Box::<[T]>::clone_from Avoid dropping and reallocating when cloning to an existing box if the lengths are the same. It would be nice if this could also be specialized for `Copy` but I don't know how that works since it's not on stable. Will gladly look into it if it's deemed as a good idea. This is my first PR with code, hope I did everything right :smile:

Override Box::<[T]>::clone_from

2020-05-23T13:08:53+00:00