A "clearfix" mixin for LESS

/*
    A LESS mixin for clearing any element within your CSS.
    This means you can avoid any extra classes in your HTML.
    However, this *WILL* bloat your compiled CSS files if you
    use it on a lot of elements, so use with caution.

    Note that you can still add a "clearfix" class to HTML
    elements if you wish: the LESS compiles to a usable CSS
    class too.

    Matt Hill, 2012-06-19
*/

/* LESS */
.clearfix {
    &:before,&:after {
        content:""; display:table;
    }
    &:after {
        clear:both;
    }
    zoom:1 /* For old IE, does nothing in other browsers */
}

/* HOW TO USE */

h1 {
    font-size:4em;
    .clearfix;
}

/* COMPILED CSS OUTPUT */

h1 {
    font-size:4em;
    zoom:1
}
h1:before,h1:after {
        content:""; display:table;
}
h1:after {
    clear:both
}