Crate empty_box [] [src]

EmptyBox, a way to safely move values in and out of Boxs without


EmptyBox is similar to a statically checked Box<Option<T>>:

use empty_box::EmptyBox;

// A box with a string!
let boxed = Box::new("Hello!".to_string());

// Oh no, we don't like that string.
let (string, empty) = EmptyBox::take(boxed);

// Let's make an objectively superior string, and put it into the original
// box.
let superior = "Objectively superior string!".to_string();

// Now we have our superior string in the box!
let boxed = empty.put(superior); 

assert_eq!("Hello!", string);
assert_eq!("Objectively superior string!", &*boxed);

Creating an EmptyBox from a Box and then putting a T back into the EmptyBox will avoid allocating a new Box, instead reusing whatever old Box the T was EmptyBox::taken from.



An "emptied" Box. Constructed via EmptyBox::take(), an EmptyBox<T> is a Box from which the contents have been moved. This allows for reuse of the Box via EmptyBox::put(), which moves the contents back in, turning the EmptyBox back into a Box<T>.