rust/compiler/rustc_mir_dataflow/src
bors 8a7ca936e6 Auto merge of #105587 - tgross35:once-cell-min, r=m-ou-se
Partial stabilization of `once_cell`

This PR aims to stabilize a portion of the `once_cell` feature:

- `core::cell::OnceCell`
- `std::cell::OnceCell` (re-export of the above)
- `std::sync::OnceLock`

This will leave `LazyCell` and `LazyLock` unstabilized, which have been moved to the `lazy_cell` feature flag.

Tracking issue: https://github.com/rust-lang/rust/issues/74465 (does not fully close, but it may make sense to move to a new issue)

Future steps for separate PRs:
- ~~Add `#[inline]` to many methods~~ #105651
- Update cranelift usage of the `once_cell` crate
- Update rust-analyzer usage of the `once_cell` crate
- Update error messages discussing once_cell

## To be stabilized API summary

```rust
// core::cell (in core/cell/once.rs)

pub struct OnceCell<T> { .. }

impl<T> OnceCell<T> {
    pub const fn new() -> OnceCell<T>;
    pub fn get(&self) -> Option<&T>;
    pub fn get_mut(&mut self) -> Option<&mut T>;
    pub fn set(&self, value: T) -> Result<(), T>;
    pub fn get_or_init<F>(&self, f: F) -> &T where F: FnOnce() -> T;
    pub fn into_inner(self) -> Option<T>;
    pub fn take(&mut self) -> Option<T>;
}

impl<T: Clone> Clone for OnceCell<T>;
impl<T: Debug> Debug for OnceCell<T>
impl<T> Default for OnceCell<T>;
impl<T> From<T> for OnceCell<T>;
impl<T: PartialEq> PartialEq for OnceCell<T>;
impl<T: Eq> Eq for OnceCell<T>;
```

```rust
// std::sync (in std/sync/once_lock.rs)

impl<T> OnceLock<T> {
    pub const fn new() -> OnceLock<T>;
    pub fn get(&self) -> Option<&T>;
    pub fn get_mut(&mut self) -> Option<&mut T>;
    pub fn set(&self, value: T) -> Result<(), T>;
    pub fn get_or_init<F>(&self, f: F) -> &T where F: FnOnce() -> T;
    pub fn into_inner(self) -> Option<T>;
    pub fn take(&mut self) -> Option<T>;
}

impl<T: Clone> Clone for OnceLock<T>;
impl<T: Debug> Debug for OnceLock<T>;
impl<T> Default for OnceLock<T>;
impl<#[may_dangle] T> Drop for OnceLock<T>;
impl<T> From<T> for OnceLock<T>;
impl<T: PartialEq> PartialEq for OnceLock<T>
impl<T: Eq> Eq for OnceLock<T>;
impl<T: RefUnwindSafe + UnwindSafe> RefUnwindSafe for OnceLock<T>;
unsafe impl<T: Send> Send for OnceLock<T>;
unsafe impl<T: Sync + Send> Sync for OnceLock<T>;
impl<T: UnwindSafe> UnwindSafe for OnceLock<T>;
```

No longer planned as part of this PR, and moved to the `rust_cell_try` feature gate:

```rust
impl<T> OnceCell<T> {
    pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E> where F: FnOnce() -> Result<T, E>;
}

impl<T> OnceLock<T> {
    pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E> where F: FnOnce() -> Result<T, E>;
}
```

I am new to this process so would appreciate mentorship wherever needed.
2023-03-30 10:12:23 +00:00
..
framework Remove DropAndReplace terminator 2023-03-07 14:25:22 +01:00
impls Introduce a no-op PlaceMention statement for let _ =. 2023-03-09 17:45:13 +00:00
move_paths Introduce a no-op PlaceMention statement for let _ =. 2023-03-09 17:45:13 +00:00
drop_flag_effects.rs Treat Drop as a rmw operation 2023-01-30 00:20:40 +01:00
elaborate_drops.rs Move mir::Fieldabi::FieldIdx 2023-03-28 22:22:37 -07:00
errors.rs Migrate all diagnostics 2022-10-23 10:09:44 +02:00
lib.rs Stabilize a portion of 'once_cell' 2023-03-29 18:04:44 -04:00
rustc_peek.rs Rollup merge of #99027 - tmiasko:basic-blocks, r=oli-obk 2022-08-29 06:34:43 +02:00
storage.rs Replace Body::basic_blocks() with field access 2022-08-26 14:27:08 +02:00
un_derefer.rs Auto merge of #99667 - ouz-a:some_branch, r=oli-obk 2022-07-29 07:11:50 +00:00
value_analysis.rs Move mir::Fieldabi::FieldIdx 2023-03-28 22:22:37 -07:00