Crate leer

Trait to abstract over types that have a notion of “being empty” and can create such an empty instance. See Empty. Intended to be a foundational crate.

Examples

Using the trait:

use leer::Empty;

let v = String::empty();

Mostly useful for something like this:

use leer::Empty;

// Of course, in this specific case, `FromIterator` would be better. But
// you get the point.
fn one_two_three<C: Empty + Extend<u32>>() -> C {
    let mut out = C::empty();
    out.extend([1, 2, 3]);
    out
}

let vec: Vec<_> = one_two_three();
let vec: std::collections::LinkedList<_> = one_two_three();

Crate features

• derive: if enabled, you can #[derive(Empty)] for structs.

Traits

Empty

Types that have a notion of “being empty” and can create such an empty instance.

Derive Macros

Empty

Derive macro for Empty.