InplaceBox

InplaceBox is a Rust library that provides a stack-allocated container similar to Box, but without heap allocation. It stores data inline within a fixed-size buffer.

Features

• Store values on the stack without heap allocation
• Support for dynamically sized types (like trait objects)
• Similar interface to Box with Deref and DerefMut implementations

Usage

use inplace_box::InplaceBox;

trait MyTrait {
    fn method(&self) -> i32;
}

struct MyStruct(i32);

impl MyTrait for MyStruct {
    fn method(&self) -> i32 {
        self.0
    }
}

fn main() {
    let inplace_box = InplaceBox::<dyn MyTrait>::new(MyStruct(42));
    assert_eq!(inplace_box.method(), 42);
}

Requirements

This crate requires the nightly Rust compiler as it uses the following unstable features:

• generic_const_exprs
• ptr_metadata
• unsize
• coerce_unsized

How It Works

InplaceBox uses Rust's advanced type system features to:

1. Store the data in a fixed-size inline buffer
2. Store vtable metadata for trait objects
3. Implement smart pointer traits for seamless usage

It's ideal for embedded systems, performance-critical code, or situations where heap allocations should be avoided.

License

MIT

Contributions

Contributions are welcome! Please feel free to submit a Pull Request.