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# static-arena

A bump-pointer arena whose buffer lives entirely on the stack (or in `static` storage). Zero `malloc`, zero `free`, so it composes with the `#[no_alloc]` real-time contract.

Because C+ does not yet have const-generic struct parameters, it ships two fixed shapes with an identical surface: `StaticArena16K` (16 KiB) and `StaticArena64K` (64 KiB). The alignment and zeroing overloads are folded into one signature with default-valued labeled parameters — `alloc_bytes(count, aligned_to: usize = 8, zeroed: bool = false)` — alongside `alloc[T]` for a single Copy value, `alloc_str`, `reset`, and the `capacity` / `used` / `remaining` accessors.

```cplus
import "static-arena/static-arena" as sa;
import "stdlib/option" as option;

var a: sa::StaticArena16K = sa::StaticArena16K::new();
guard let option::Option[*u8]::Some(p) = a.alloc_bytes(64 as usize, aligned_to: 8 as usize) else {
    return 1;   // OOM
};
// ... use p ...
a.reset();      // recover full capacity, reuse
```

The stack size ceiling is roughly 128 KiB; for larger arenas, allocate in `static` and reference by pointer, or use the heap-backed [arena](/docs/packages/arena).