box_syntax - The Rust Unstable Book

# `box_syntax`

The tracking issue for this feature is: #49733

See also `box_patterns`

Currently the only stable way to create a `Box` is via the `Box::new` method. Also it is not possible in stable Rust to destructure a `Box` in a match pattern. The unstable `box` keyword can be used to create a `Box`. An example usage would be:

    #![feature(box_syntax)]

    fn main() {
        let b = box 5;
    }