Struct With

pub struct With<Q>(/* private fields */);

A Query which matches if query Q matches.

Unlike Q however, With<Q> does not provide access to the data returned by Q. This is useful for avoiding access conflicts.

Example: &C requires read-only access to component C, but With<&C> does not require access at all.

Implementations

impl<Q> With<Q>

pub const fn new() -> With<Q>

Create a new instance.

Trait Implementations

impl<Q> Clone for With<Q>

fn clone(&self) -> With<Q>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Q> Debug for With<Q>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<Q> Default for With<Q>

fn default() -> With<Q>

Returns the “default value” for a type.

impl<Q> Query for With<Q>

where Q: Query,

type Item<'a> = With<Q>

The item returned by this query. This is usually the same type as Self, but with a modified lifetime.

type ArchState = ()

Per-archetype state, e.g. pointers to archetype columns.

type State = <Q as Query>::State

Cached data for fetch initialization, e.g. component indices.

fn init( world: &mut World, config: &mut HandlerConfig, ) -> Result<(ComponentAccess, <With<Q> as Query>::State), InitError>

Initialize the query. Returns an expression describing the components accessed by the query and a new instance of Self::State.

fn new_state(world: &mut World) -> <With<Q> as Query>::State

Returns a new Self::State instance.

fn new_arch_state( arch: &Archetype, state: &mut <With<Q> as Query>::State, ) -> Option<<With<Q> as Query>::ArchState>

Returns a new Self::ArchState instance.

unsafe fn get<'a>( _state: &<With<Q> as Query>::ArchState, _row: ArchetypeRow, ) -> <With<Q> as Query>::Item<'a>

Gets the query item at the given row in the archetype.

impl<Q> Copy for With<Q>

impl<Q> ReadOnlyQuery for With<Q>

where Q: Query,