Fixes#73268
When a deref coercion occurs, we may end up with a move error if the
base value has been partially moved out of. However, we do not indicate
anywhere that a deref coercion is occuring, resulting in an error
message with a confusing span.
This PR adds an explicit note to move errors when a deref coercion is
involved. We mention the name of the type that the deref-coercion
resolved to, as well as the `Deref::Target` associated type being used.
BTreeMap: move up reference to map's root from NodeRef
Since the introduction of `NodeRef` years ago, it also contained a mutable reference to the owner of the root node of the tree (somewhat disguised as *const). Its intent is to be used only when the rest of the `NodeRef` is no longer needed. Moving this to where it's actually used, thought me 2 things:
- Some sort of "postponed mutable reference" is required in most places that it is/was used, and that's exactly where we also need to store a reference to the length (number of elements) of the tree, for the same reason. The length reference can be a normal reference, because the tree code does not care about tree length (just length per node).
- It's downright obfuscation in `from_sorted_iter` (transplanted to #75329)
- It's one of the reasons for the scary notice on `reborrow_mut`, the other one being addressed in #73971.
This does repeat the raw pointer code in a few places, but it could be bundled up with the length reference.
r? `@Mark-Simulacrum`
Use intra-doc links in `core::ptr`
Part of #75080.
The only link that I did not change is a link to a function on the
`pointer` primitive because intra-doc links for the `pointer` primitive
don't work yet (see #63351).
---
@rustbot modify labels: A-intra-doc-links T-doc
Add drain_filter method to HashMap and HashSet
Add `HashMap::drain_filter` and `HashSet::drain_filter`, implementing part of rust-lang/rfcs#2140. These new methods are unstable. The tracking issue is #59618.
The added iterators behave the same as `BTreeMap::drain_filter` and `BTreeSet::drain_filter`, except their iteration order is arbitrary. The unit tests are adapted from `alloc::collections::btree`.
This branch rewrites `HashSet` to be a wrapper around `hashbrown::HashSet` rather than `std::collections::HashMap`.
(Both are themselves wrappers around `hashbrown::HashMap`, so the in-memory representation is the same either way.) This lets `std` re-use more iterator code from `hashbrown`. Without this change, we would need to duplicate much more code to implement `HashSet::drain_filter`.
This branch also updates the `hashbrown` crate to version 0.9.0. Aside from changes related to the `DrainFilter` iterators, this version only changes features that are not used in libstd or rustc. And it updates `indexmap` to version 1.6.0, whose only change is compatibility with `hashbrown` 0.9.0.
This avoids overlapping a reference covering the data field,
which may be changed due in concurrent conditions. This fully
fixed the UB mainfested with `new_cyclic`.
BTreeMap mutable iterators should not take any reference to visited nodes during iteration
Fixes#73915, overlapping mutable references during BTreeMap iteration
r? `@RalfJung`
`write` is ambiguous because there's also a macro called `write`.
Also removed unnecessary and potentially confusing link to a function in
its own docs.
The only link that I did not change is a link to a function on the
`pointer` primitive because intra-doc links for the `pointer` primitive
don't work yet (see #63351).
ManuallyDrop's documentation tells the user to use MaybeUninit instead
when handling uninitialized data. However, the main functionality of
ManuallyDrop (drop) was not available directly on MaybeUninit. Adding it
makes it easier to switch from one to the other.
Implement Seek::stream_position() for BufReader
Optimization over `BufReader::seek()` for getting the current position without flushing the internal buffer.
Related to #31100. Based on the code in #70577.
Remove unneeded `#[cfg(not(test))]` from libcore
This fixes rust-analyzer inside these modules (currently it does not analyze them, assuming they're configured out).
