swaitsandClaude Opus 4.6
3102fc747a
Implement full SSD1306 OLED display support: - Splash screen on boot (1.5s) with project name, version, board - Dashboard showing radio state, config, counters, RSSI/SNR - RSSI history sparkline (64-sample ring buffer, 2px-wide bars) - DisplayOn/DisplayOff host commands routed via dedicated channel - Pure render functions against generic DrawTarget (no hardware coupling) - Display on/off control bypasses radio task entirely Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
64 lines
2.5 KiB
Markdown
64 lines
2.5 KiB
Markdown
# static-cell
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[](https://crates.io/crates/static_cell)
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[](https://crates.io/crates/static_cell)
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[](https://docs.rs/static_cell)
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Statically allocated, initialized at runtime cell.
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`StaticCell` provides a no-std-compatible, no-alloc way to reserve memory at compile time for
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a value, but initialize it at runtime, and get a `'static` reference to it.
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This is useful in the following scenarios:
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- You need `&'static T`, but `T` can't be constructed in const context so you can't simply use a `static`.
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- You need `&'static mut T`, not just `&'static T`.
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## Example
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```rust
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use static_cell::StaticCell;
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// Statically allocate memory for a `u32`.
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static SOME_INT: StaticCell<u32> = StaticCell::new();
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// Initialize it at runtime. This returns a `&'static mut`.
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let x: &'static mut u32 = SOME_INT.init(42);
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assert_eq!(*x, 42);
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// Trying to call `.init()` again would panic, because the StaticCell is already initialized.
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// SOME_INT.init(42);
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```
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## Alternatives
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- If you can use `alloc`, you can use `Box::leak()`.
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- If you're OK with `unsafe`, you can use `static mut THING: MaybeUninit<T>`.
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- If you need just `&'static T` (instead of `&'static mut T`), there's [`OnceCell`](https://doc.rust-lang.org/stable/core/cell/struct.OnceCell.html) (not thread-safe though) or [`OnceLock`](https://doc.rust-lang.org/stable/std/sync/struct.OnceLock.html) (thread-safe, but requires `std`).
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## Interoperability
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This crate uses [`portable-atomic`](https://crates.io/crates/portable-atomic), so on targets without native
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atomics you must import a crate that provides a [`critical-section`](https://github.com/rust-embedded/critical-section)
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implementation. See the `critical-section` README for details.
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## Minimum Supported Rust Version (MSRV)
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This crate is guaranteed to compile on stable Rust 1.56 and up. It might compile with
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older versions but that may change in any new patch release.
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## License
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This work is licensed under either of
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- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
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<http://www.apache.org/licenses/LICENSE-2.0>)
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- MIT license ([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
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at your option.
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## Contribution
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Unless you explicitly state otherwise, any contribution intentionally submitted
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for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
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dual licensed as above, without any additional terms or conditions.
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