# thisisplural
[](https://github.com/ryo33/thisisplural)

[](https://crates.io/crates/thisisplural)
[](https://docs.rs/thisisplural)
`#[derive(Plural)]` for creating frictionless new types with a `Vec`, `HashMap`, etc.
## Features
- Automatically implements `From`, `Into`, `FromIterator`, `IntoIterator`.
- Supports `Vec` and `HashMap` (adding other collections to here is very easy).
## Example
```rust
// This implements `From`, `Into`, `FromIterator`, `IntoIterator`, `Deref`, and `DerefMut`.
#[derive(Plural)]
struct Numbers(Vec<u32>);
// use `From` trait
let my_favorite_numbers: Numbers = vec![].into();
// `FromIterator` allows this `collect()`
let doubled_numbers: Numbers = my_favorite_numbers.0.iter().map(|x| x * 2).collect();
// `HashMap` is also supported
#[derive(Plural)]
struct FavoriteNumbers(HashMap<&'static str, Numbers>);
// construct the struct with using `FromIterator`
let favorite_numbers =
FavoriteNumbers::from_iter([("ryo33", my_favorite_numbers), ("someone", doubled_numbers)]);
// use it in a `for` loop (`IntoIterator` trait)
for (name, numbers) in favorite_numbers {
// use Deref trait
println!("{} has {} favorite number(s)", name, numbers.0.len());
}
```