Struct rin::ecs::operators::WriteOption

pub struct WriteOption<'a, T> { /* fields omitted */ }

Operator that matches every entity no matter if it has the component or not with read and write access to that component

It returns an option that will be None if the entity doesn’t have this component

for (pos, vel) in entities.iter_for_mut::<(WriteOption<Position>, Read<Velocity>)>(){
    if let Some(pos) = pos {
        // ...
    }
}

Will select all entities that optionally have Position and have a Velocity component pos will be None for those that don’t have Position

Methods from Deref<Target = Option<&'a mut T>>

#[must_use = "if you intended to assert that this has a value, consider `.unwrap()` instead"]

pub const fn is_some(&self) -> bool

Returns true if the option is a Some value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_some(), true);

let x: Option<u32> = None;
assert_eq!(x.is_some(), false);

#[must_use = "if you intended to assert that this doesn't have a value, consider \ `.and_then(|| panic!(\"`Option` had a value when expected `None`\"))` instead"]

pub const fn is_none(&self) -> bool

Returns true if the option is a None value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_none(), false);

let x: Option<u32> = None;
assert_eq!(x.is_none(), true);

#[must_use]

pub fn contains<U>(&self, x: &U) -> bool where
    U: PartialEq<T>, 

🔬 This is a nightly-only experimental API. (option_result_contains)

Returns true if the option is a Some value containing the given value.

Examples

#![feature(option_result_contains)]

let x: Option<u32> = Some(2);
assert_eq!(x.contains(&2), true);

let x: Option<u32> = Some(3);
assert_eq!(x.contains(&2), false);

let x: Option<u32> = None;
assert_eq!(x.contains(&2), false);

pub const fn as_ref(&self) -> Option<&T>

Converts from &Option<T> to Option<&T>.

Examples

Converts an Option<String> into an Option<usize>, preserving the original. The map method takes the self argument by value, consuming the original, so this technique uses as_ref to first take an Option to a reference to the value inside the original.

let text: Option<String> = Some("Hello, world!".to_string());
// First, cast `Option<String>` to `Option<&String>` with `as_ref`,
// then consume *that* with `map`, leaving `text` on the stack.
let text_length: Option<usize> = text.as_ref().map(|s| s.len());
println!("still can print text: {:?}", text);

pub fn as_mut(&mut self) -> Option<&mut T>

Converts from &mut Option<T> to Option<&mut T>.

Examples

let mut x = Some(2);
match x.as_mut() {
    Some(v) => *v = 42,
    None => {},
}
assert_eq!(x, Some(42));

pub fn as_pin_ref(self: Pin<&Option<T>>) -> Option<Pin<&T>>

Converts from Pin<&Option<T>> to Option<Pin<&T>>.

pub fn as_pin_mut(self: Pin<&mut Option<T>>) -> Option<Pin<&mut T>>

Converts from Pin<&mut Option<T>> to Option<Pin<&mut T>>.

pub const fn iter(&self) -> Iter<'_, T>

Returns an iterator over the possibly contained value.

Examples

let x = Some(4);
assert_eq!(x.iter().next(), Some(&4));

let x: Option<u32> = None;
assert_eq!(x.iter().next(), None);

pub fn iter_mut(&mut self) -> IterMut<'_, T>

Returns a mutable iterator over the possibly contained value.

Examples

let mut x = Some(4);
match x.iter_mut().next() {
    Some(v) => *v = 42,
    None => {},
}
assert_eq!(x, Some(42));

let mut x: Option<u32> = None;
assert_eq!(x.iter_mut().next(), None);

pub fn insert(&mut self, value: T) -> &mut T

Inserts value into the option then returns a mutable reference to it.

If the option already contains a value, the old value is dropped.

See also Option::get_or_insert, which doesn’t update the value if the option already contains Some.

Example

let mut opt = None;
let val = opt.insert(1);
assert_eq!(*val, 1);
assert_eq!(opt.unwrap(), 1);
let val = opt.insert(2);
assert_eq!(*val, 2);
*val = 3;
assert_eq!(opt.unwrap(), 3);

pub fn get_or_insert(&mut self, value: T) -> &mut T

Inserts value into the option if it is None, then returns a mutable reference to the contained value.

See also Option::insert, which updates the value even if the option already contains Some.

Examples

let mut x = None;

{
    let y: &mut u32 = x.get_or_insert(5);
    assert_eq!(y, &5);

    *y = 7;
}

assert_eq!(x, Some(7));

pub fn get_or_insert_default(&mut self) -> &mut T where
    T: Default, 

🔬 This is a nightly-only experimental API. (option_get_or_insert_default)

Inserts the default value into the option if it is None, then returns a mutable reference to the contained value.

Examples

#![feature(option_get_or_insert_default)]

let mut x = None;

{
    let y: &mut u32 = x.get_or_insert_default();
    assert_eq!(y, &0);

    *y = 7;
}

assert_eq!(x, Some(7));

pub fn get_or_insert_with<F>(&mut self, f: F) -> &mut T where
    F: FnOnce() -> T, 

Inserts a value computed from f into the option if it is None, then returns a mutable reference to the contained value.

Examples

let mut x = None;

{
    let y: &mut u32 = x.get_or_insert_with(|| 5);
    assert_eq!(y, &5);

    *y = 7;
}

assert_eq!(x, Some(7));

pub fn take(&mut self) -> Option<T>

Takes the value out of the option, leaving a None in its place.

Examples

let mut x = Some(2);
let y = x.take();
assert_eq!(x, None);
assert_eq!(y, Some(2));

let mut x: Option<u32> = None;
let y = x.take();
assert_eq!(x, None);
assert_eq!(y, None);

pub fn replace(&mut self, value: T) -> Option<T>

Replaces the actual value in the option by the value given in parameter, returning the old value if present, leaving a Some in its place without deinitializing either one.

Examples

let mut x = Some(2);
let old = x.replace(5);
assert_eq!(x, Some(5));
assert_eq!(old, Some(2));

let mut x = None;
let old = x.replace(3);
assert_eq!(x, Some(3));
assert_eq!(old, None);

pub fn as_deref(&self) -> Option<&<T as Deref>::Target>

Converts from Option<T> (or &Option<T>) to Option<&T::Target>.

Leaves the original Option in-place, creating a new one with a reference to the original one, additionally coercing the contents via Deref.

Examples

let x: Option<String> = Some("hey".to_owned());
assert_eq!(x.as_deref(), Some("hey"));

let x: Option<String> = None;
assert_eq!(x.as_deref(), None);

pub fn as_deref_mut(&mut self) -> Option<&mut <T as Deref>::Target>

Converts from Option<T> (or &mut Option<T>) to Option<&mut T::Target>.

Leaves the original Option in-place, creating a new one containing a mutable reference to the inner type’s Deref::Target type.

Examples

let mut x: Option<String> = Some("hey".to_owned());
assert_eq!(x.as_deref_mut().map(|x| {
    x.make_ascii_uppercase();
    x
}), Some("HEY".to_owned().as_mut_str()));

Trait Implementations

impl<'a, T> DataAccesses for WriteOption<'a, T> where
    T: Component,
    <T as Component>::Storage: for<'s> Storage<'s, T>, 

pub fn reads() -> Vec<TypeId, Global>

pub fn writes() -> Vec<TypeId, Global>

impl<'a, T> Deref for WriteOption<'a, T> where
    T: Component, 

type Target = Option<&'a mut T>

The resulting type after dereferencing.

pub fn deref(&self) -> &Option<&'a mut T>

Dereferences the value.

impl<'a, T> DerefMut for WriteOption<'a, T> where
    T: Component, 

pub fn deref_mut(&mut self) -> &mut Option<&'a mut T>

Mutably dereferences the value.

impl<'a, T> FromComponent<'a, Option<&'a mut T>> for WriteOption<'a, T> where
    T: Component, 

pub fn from_component(component: Option<&'a mut T>) -> WriteOption<'a, T>

impl<'a, T> UnorderedData<'a> for WriteOption<'a, T> where
    T: Component,
    <T as Component>::Storage: for<'s> Storage<'s, T>, 

type Iter = IterOptionMut<'a, T, WriteGuardRef<'a, <T as Component>::Storage, <T as Component>::MutStorageCacheGuard>>

type IterMut = IterOptionMut<'a, T, WriteGuardRef<'a, <T as Component>::Storage, <T as Component>::MutStorageCacheGuard>>

type Components = T

type ComponentsRef = Option<<<T as Component>::Storage as Storage<'a, T>>::GetMut>

type Storage = StorageOptionMut<'a, T, WriteGuardRef<'a, <T as Component>::Storage, <T as Component>::MutStorageCacheGuard>>

pub fn query_mask<E>(entities: &E) -> Bitmask where
    E: EntitiesStorage, 

pub fn into_iter<E>(
    entities: &'a E
) -> <WriteOption<'a, T> as UnorderedData<'a>>::Iter where
    E: EntitiesStorage, 

pub fn into_iter_mut<E>(
    entities: &'a E
) -> <WriteOption<'a, T> as UnorderedData<'a>>::Iter where
    E: EntitiesStorage, 

pub fn storage<E>(
    entities: &'a E
) -> Option<<WriteOption<'a, T> as UnorderedData<'a>>::Storage> where
    E: EntitiesStorage, 

impl<'_, '_, T> SafeIter<'_> for WriteOption<'_, T>