Struct InRef

pub struct InRef<'i, T: ?Sized>(pub &'i T);

A SystemInput type which denotes that a System receives a read-only reference to a value of type T from its caller.

This is similar to In but takes a reference to a value instead of the value itself. See InMut for the mutable version.

See SystemInput to learn more about system inputs in general.

Examples

Here is a simple example of a system that logs the passed in message.

#[derive(Resource, Default)]
struct Log(String);

fn log(InRef(msg): InRef<str>, mut log: ResMut<Log>) {
    writeln!(log.0, "{}", msg).unwrap();
}

let mut world = World::new();
world.init_resource::<Log>();
let mut log_system = IntoSystem::into_system(log);
log_system.initialize(&mut world);

log_system.run("Hello, world!", &mut world);

Tuple Fields

0: &'i T

Trait Implementations

impl<'i, T: Debug + ?Sized> Debug for InRef<'i, T>

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

Formats the value using the given formatter.

impl<'i, T: ?Sized> Deref for InRef<'i, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T: ?Sized + 'static> SystemInput for InRef<'_, T>

type Param<'i> = InRef<'i, T>

The wrapper input type that is defined as the first argument to FunctionSystems.

type Inner<'i> = &'i T

The inner input type that is passed to functions that run systems, such as System::run.

fn wrap(this: Self::Inner<'_>) -> Self::Param<'_>

Converts a SystemInput::Inner into a SystemInput::Param.