# `unsized-vec`
[](https://docs.rs/unsized-vec/) [](https://crates.io/crates/unsized-vec)
Say goodbye to `Vec<Box<dyn Any>>`! Cut down on your heap allocations.
`UnsizedVec<T>` is like [`Vec<T>`](https://doc.rust-lang.org/alloc/vec/struct.Vec.html), but `T` can be `?Sized`.
## Features
- Familiar `Vec` API.
- Same time complexity as `alloc::vec::Vec` for major operations(indexing, push, pop, insert, remove).
- When `T`'s alignment is not known at compile time (e.g. `T` is a trait object), this rule has one expection,
explained in the crate docs.
- For `T: Sized`, `UnsizedVec<T>` compiles to a newtype around `alloc::vec::Vec`, and can be trivially converted to/from it.
- For unsized `T`, there are two heap allocations: one for the elements, and one for the pointer metadata.
- `#[no_std]` (but requires `alloc`).
## Drawbacks
- Invariant in `T`.
- Experimental, nightly-only.
## Example
```rust
#![feature(unsized_fn_params)]
use core::fmt::Debug;
use emplacable::box_new_with;
use unsized_vec::{unsize_vec, UnsizedVec};
fn main() {
let mut vec: UnsizedVec<dyn Debug> = unsize_vec![27.53_f32, "oh the places we'll go", Some(())];
for traitobj in &vec {
dbg!(traitobj);
};
assert_eq!(vec.len(), 3);
let maybe_popped: Option<Box<dyn Debug>> = vec.pop_into().map(box_new_with);
let popped = maybe_popped.unwrap();
dbg!(&*popped);
assert_eq!(vec.len(), 2);
}
```
## License
`unsized-vec` is distributed under the terms of both the MIT license and the Apache License (Version 2.0).
See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.