Struct FilteredAccess 

pub struct FilteredAccess { /* private fields */ }

An Access that has been filtered to include and exclude certain combinations of elements.

Used internally to statically check if queries are disjoint.

Subtle: a read or write in access should not be considered to imply a with access.

For example consider Query<Option<&T>> this only has a read of T as doing otherwise would allow for queries to be considered disjoint when they shouldn’t:

• Query<(&mut T, Option<&U>)> read/write T, read U, with U
• Query<&mut T, Without<U>> read/write T, without U from this we could reasonably conclude that the queries are disjoint but they aren’t.

In order to solve this the actual access that Query<(&mut T, Option<&U>)> has is read/write T, read U. It must still have a read U access otherwise the following queries would be incorrectly considered disjoint:

• Query<&mut T> read/write T
• Query<Option<&T>> accesses nothing

See comments the WorldQuery impls of AnyOf/Option/Or for more information.

Implementations

impl FilteredAccess

pub fn matches_everything() -> FilteredAccess

Returns a FilteredAccess which has no access and matches everything. This is the equivalent of a TRUE logic atom.

pub fn matches_nothing() -> FilteredAccess

Returns a FilteredAccess which has no access and matches nothing. This is the equivalent of a FALSE logic atom.

pub fn access(&self) -> &Access

Returns a reference to the underlying unfiltered access.

pub fn access_mut(&mut self) -> &mut Access

Returns a mutable reference to the underlying unfiltered access.

pub fn add_component_read(&mut self, index: ComponentId)

Adds access to the component given by index.

pub fn add_component_write(&mut self, index: ComponentId)

Adds exclusive access to the component given by index.

pub fn add_resource_read(&mut self, index: ComponentId)

Adds access to the resource given by index.

pub fn add_resource_write(&mut self, index: ComponentId)

Adds exclusive access to the resource given by index.

pub fn and_with(&mut self, index: ComponentId)

Adds a With filter: corresponds to a conjunction (AND) operation.

Suppose we begin with Or<(With<A>, With<B>)>, which is represented by an array of two AccessFilter instances. Adding AND With<C> via this method transforms it into the equivalent of Or<((With<A>, With<C>), (With<B>, With<C>))>.

pub fn and_without(&mut self, index: ComponentId)

Adds a Without filter: corresponds to a conjunction (AND) operation.

Suppose we begin with Or<(With<A>, With<B>)>, which is represented by an array of two AccessFilter instances. Adding AND Without<C> via this method transforms it into the equivalent of Or<((With<A>, Without<C>), (With<B>, Without<C>))>.

pub fn append_or(&mut self, other: &FilteredAccess)

Appends an array of filters: corresponds to a disjunction (OR) operation.

As the underlying array of filters represents a disjunction, where each element (AccessFilters) represents a conjunction, we can simply append to the array.

pub fn extend_access(&mut self, other: &FilteredAccess)

Adds all of the accesses from other to self.

pub fn is_compatible(&self, other: &FilteredAccess) -> bool

Returns true if this and other can be active at the same time.

pub fn get_conflicts(&self, other: &FilteredAccess) -> AccessConflicts

Returns a vector of elements that this and other cannot access at the same time.

pub fn extend(&mut self, other: &FilteredAccess)

Adds all access and filters from other.

Corresponds to a conjunction operation (AND) for filters.

Extending Or<(With<A>, Without<B>)> with Or<(With<C>, Without<D>)> will result in Or<((With<A>, With<C>), (With<A>, Without<D>), (Without<B>, With<C>), (Without<B>, Without<D>))>.

pub fn read_all(&mut self)

Sets the underlying unfiltered access as having access to all indexed elements.

pub fn write_all(&mut self)

Sets the underlying unfiltered access as having mutable access to all indexed elements.

pub fn read_all_components(&mut self)

Sets the underlying unfiltered access as having access to all components.

pub fn write_all_components(&mut self)

Sets the underlying unfiltered access as having mutable access to all components.

pub fn is_subset(&self, other: &FilteredAccess) -> bool

Returns true if the set is a subset of another, i.e. other contains at least all the values in self.

pub fn with_filters(&self) -> impl Iterator<Item = ComponentId>

Returns the indices of the elements that this access filters for.

pub fn without_filters(&self) -> impl Iterator<Item = ComponentId>

Returns the indices of the elements that this access filters out.

pub fn contains(&self, index: ComponentId) -> bool

Returns true if the index is used by this FilteredAccess in filters or archetypal access. This includes most ways to access a component, but notably excludes EntityRef and EntityMut along with anything inside Option<T>.

Trait Implementations

impl Clone for FilteredAccess

fn clone(&self) -> FilteredAccess

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FilteredAccess

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

Formats the value using the given formatter.

impl Default for FilteredAccess

fn default() -> FilteredAccess

Returns the “default value” for a type.

impl From<FilteredAccess> for FilteredAccessSet

fn from(filtered_access: FilteredAccess) -> FilteredAccessSet

Converts to this type from the input type.

impl PartialEq for FilteredAccess

fn eq(&self, other: &FilteredAccess) -> 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 FilteredAccess

impl StructuralPartialEq for FilteredAccess