Struct ComponentKey 

pub struct ComponentKey { /* private fields */ }

An identifier for a component

Implementations

impl ComponentKey

pub fn of<T: Component>() -> Self

Get the component key of a type

Examples found in repository

examples/query.rs (line 54)

fn main() {
    let mut world = World::new();

    for i in 0..5 {
        let ent = world.spawn();

        world.add(ent, Tag);
        world.add(ent, Name("Object"));

        if i % 2 == 0 {
            world.add(ent, Num(i));
        }
    }

    {
        let ent = world.spawn();
        world.add(ent, Num(1337));
    }

    /// Query with component tuple
    let query = world.query::<(Tag, Num)>();
    for e in &query {
        println!("Entity #{e} has both `Tag` and `Num`");
    }

    /// you can also use `Exclude` to ensure some components are not included
    for e in &world.query::<(Tag, Exclude<(Num,)>)>() {
        println!("Entity #{e} has `Tag` without `Num`");
    }

    // `Filter` allows for more fine-grained control.
    // In fact, the (Component1, Component2, ...) tuple implements `ToFilter` so it can be used in a query
    //
    // `ComponentKey` is used to identify component types,
    // the `component_id` macro can be used as a shorthand to `ComponentKey` functions.
    let filter = Filter::new()
        .with_include(&[ComponentKey::of::<Tag>(), ComponentKey::of::<Name>()])
        .with_exclude(&[component_id!(Num)]);

    for _ in &world.query_filter(filter) {
        // do stuff
    }
}

pub fn from_value<T: Component>(value: &T) -> Self

Get a component key from a value

Trait Implementations

impl Clone for ComponentKey

fn clone(&self) -> ComponentKey

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Hash for ComponentKey

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ComponentKey

fn eq(&self, other: &ComponentKey) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ComponentKey

impl StructuralPartialEq for ComponentKey