Trait List
pub trait List: PartialReflect {
// Required methods
fn get(&self, index: usize) -> Option<&(dyn PartialReflect + 'static)>;
fn get_mut(
&mut self,
index: usize,
) -> Option<&mut (dyn PartialReflect + 'static)>;
fn insert(&mut self, index: usize, element: Box<dyn PartialReflect>);
fn remove(&mut self, index: usize) -> Box<dyn PartialReflect>;
fn len(&self) -> usize;
fn iter(&self) -> ListIter<'_> ⓘ;
fn drain(&mut self) -> Vec<Box<dyn PartialReflect>>;
// Provided methods
fn push(&mut self, value: Box<dyn PartialReflect>) { ... }
fn pop(&mut self) -> Option<Box<dyn PartialReflect>> { ... }
fn is_empty(&self) -> bool { ... }
fn to_dynamic_list(&self) -> DynamicList { ... }
fn get_represented_list_info(&self) -> Option<&'static ListInfo> { ... }
}Expand description
A trait used to power list-like operations via reflection.
This corresponds to types, like Vec, which contain an ordered sequence
of elements that implement Reflect.
Unlike the Array trait, implementors of this trait are not expected to
maintain a constant length.
Methods like insertion and removal explicitly allow for their
internal size to change.
push and pop have default implementations,
however it will generally be more performant to implement them manually
as the default implementation uses a very naive approach to find the correct position.
This trait expects its elements to be ordered linearly from front to back. The front element starts at index 0 with the back element ending at the largest index. This contract above should be upheld by any manual implementors.
Due to the type-erasing nature of the reflection API as a whole, this trait does not make any guarantees that the implementor’s elements are homogeneous (i.e. all the same type).
§Example
use bevy_reflect::{PartialReflect, Reflect, List};
let foo: &mut dyn List = &mut vec![123_u32, 456_u32, 789_u32];
assert_eq!(foo.len(), 3);
let last_field: Box<dyn PartialReflect> = foo.pop().unwrap();
assert_eq!(last_field.try_downcast_ref::<u32>(), Some(&789));Required Methods§
fn get(&self, index: usize) -> Option<&(dyn PartialReflect + 'static)>
fn get(&self, index: usize) -> Option<&(dyn PartialReflect + 'static)>
Returns a reference to the element at index, or None if out of bounds.
fn get_mut(
&mut self,
index: usize,
) -> Option<&mut (dyn PartialReflect + 'static)>
fn get_mut( &mut self, index: usize, ) -> Option<&mut (dyn PartialReflect + 'static)>
Returns a mutable reference to the element at index, or None if out of bounds.
fn insert(&mut self, index: usize, element: Box<dyn PartialReflect>)
fn insert(&mut self, index: usize, element: Box<dyn PartialReflect>)
Inserts an element at position index within the list,
shifting all elements after it towards the back of the list.
§Panics
Panics if index > len.
fn remove(&mut self, index: usize) -> Box<dyn PartialReflect>
fn remove(&mut self, index: usize) -> Box<dyn PartialReflect>
Removes and returns the element at position index within the list,
shifting all elements before it towards the front of the list.
§Panics
Panics if index is out of bounds.
fn drain(&mut self) -> Vec<Box<dyn PartialReflect>>
fn drain(&mut self) -> Vec<Box<dyn PartialReflect>>
Drain the elements of this list to get a vector of owned values.
After calling this function, self will be empty. The order of items in the returned
Vec will match the order of items in self.
Provided Methods§
fn push(&mut self, value: Box<dyn PartialReflect>)
fn push(&mut self, value: Box<dyn PartialReflect>)
Appends an element to the back of the list.
fn pop(&mut self) -> Option<Box<dyn PartialReflect>>
fn pop(&mut self) -> Option<Box<dyn PartialReflect>>
Removes the back element from the list and returns it, or None if it is empty.
fn to_dynamic_list(&self) -> DynamicList
fn to_dynamic_list(&self) -> DynamicList
Creates a new DynamicList from this list.
fn get_represented_list_info(&self) -> Option<&'static ListInfo>
fn get_represented_list_info(&self) -> Option<&'static ListInfo>
Will return None if TypeInfo is not available.