pub trait Map: Reflect {
// Required methods
fn get(&self, key: &dyn Reflect) -> Option<&dyn Reflect>;
fn get_mut(&mut self, key: &dyn Reflect) -> Option<&mut dyn Reflect>;
fn get_at(&self, index: usize) -> Option<(&dyn Reflect, &dyn Reflect)>;
fn get_at_mut(
&mut self,
index: usize,
) -> Option<(&dyn Reflect, &mut dyn Reflect)>;
fn len(&self) -> usize;
fn iter(&self) -> MapIter<'_> ⓘ;
fn drain(self: Box<Self>) -> Vec<(Box<dyn Reflect>, Box<dyn Reflect>)>;
fn clone_dynamic(&self) -> DynamicMap;
fn insert_boxed(
&mut self,
key: Box<dyn Reflect>,
value: Box<dyn Reflect>,
) -> Option<Box<dyn Reflect>>;
fn remove(&mut self, key: &dyn Reflect) -> Option<Box<dyn Reflect>>;
// Provided method
fn is_empty(&self) -> bool { ... }
}
Expand description
A trait used to power map-like operations via reflection.
Maps contain zero or more entries of a key and its associated value,
and correspond to types like HashMap
.
The order of these entries is not guaranteed by this trait.
§Hashing
All keys are expected to return a valid hash value from Reflect::reflect_hash
.
If using the #[derive(Reflect)]
macro, this can be done by adding #[reflect(Hash)]
to the entire struct or enum.
This is true even for manual implementors who do not use the hashed value,
as it is still relied on by DynamicMap
.
§Example
use bevy_reflect::{Reflect, Map};
use bevy_utils::HashMap;
let foo: &mut dyn Map = &mut HashMap::<u32, bool>::new();
foo.insert_boxed(Box::new(123_u32), Box::new(true));
assert_eq!(foo.len(), 1);
let field: &dyn Reflect = foo.get(&123_u32).unwrap();
assert_eq!(field.downcast_ref::<bool>(), Some(&true));
Required Methods§
Sourcefn get(&self, key: &dyn Reflect) -> Option<&dyn Reflect>
fn get(&self, key: &dyn Reflect) -> Option<&dyn Reflect>
Returns a reference to the value associated with the given key.
If no value is associated with key
, returns None
.
Sourcefn get_mut(&mut self, key: &dyn Reflect) -> Option<&mut dyn Reflect>
fn get_mut(&mut self, key: &dyn Reflect) -> Option<&mut dyn Reflect>
Returns a mutable reference to the value associated with the given key.
If no value is associated with key
, returns None
.
Sourcefn get_at(&self, index: usize) -> Option<(&dyn Reflect, &dyn Reflect)>
fn get_at(&self, index: usize) -> Option<(&dyn Reflect, &dyn Reflect)>
Returns the key-value pair at index
by reference, or None
if out of bounds.
Sourcefn get_at_mut(
&mut self,
index: usize,
) -> Option<(&dyn Reflect, &mut dyn Reflect)>
fn get_at_mut( &mut self, index: usize, ) -> Option<(&dyn Reflect, &mut dyn Reflect)>
Returns the key-value pair at index
by reference where the value is a mutable reference, or None
if out of bounds.
Sourcefn drain(self: Box<Self>) -> Vec<(Box<dyn Reflect>, Box<dyn Reflect>)>
fn drain(self: Box<Self>) -> Vec<(Box<dyn Reflect>, Box<dyn Reflect>)>
Drain the key-value pairs of this map to get a vector of owned values.
Sourcefn clone_dynamic(&self) -> DynamicMap
fn clone_dynamic(&self) -> DynamicMap
Clones the map, producing a DynamicMap
.
Sourcefn insert_boxed(
&mut self,
key: Box<dyn Reflect>,
value: Box<dyn Reflect>,
) -> Option<Box<dyn Reflect>>
fn insert_boxed( &mut self, key: Box<dyn Reflect>, value: Box<dyn Reflect>, ) -> Option<Box<dyn Reflect>>
Inserts a key-value pair into the map.
If the map did not have this key present, None
is returned.
If the map did have this key present, the value is updated, and the old value is returned.