fn matches(elem: &dom::ElementData, selector: &css::Selector) -> bool {
    // match all selectors, simple and compound
    match *selector {
        css::Selector::Simple(ref simple_selector) => matches_simple_selector(
            elem, simple_selector)
    }
}
// If a selector matches an element
If a selector matches an element
If a selector matches an element
fn matches(elem: &dom::ElementData, selector: &css::Selector) -> bool {
    // match all selectors, simple and compound
    match *selector {
        css::Selector::Simple(ref simple_selector) => matches_simple_selector(
            elem, simple_selector)
    }
}
fn matches ( elem : & dom :: ElementData , selector : & css :: Selector ) -> bool { // match all selectors, simple and compound match * selector { css :: Selector :: Simple ( ref simple_selector ) => matches_simple_selector ( elem , simple_selector ) } }
If a selector matches an element
If a selector matches an element
elem
&dom::ElementData
selector
&css::Selector
elem
&dom::ElementData
selector
&css::Selector