Struct Container 

pub struct Container { /* private fields */ }

A type-keyed service container for dependency injection.

See the module documentation for usage examples.

Implementations

impl Container

pub fn new() -> Self

Create an empty container.

pub fn register<T: Send + Sync + 'static>(&mut self, service: T) -> &mut Self

Register a concrete service by value.

Wraps service in Arc<T> and stores it under TypeId::of::<T>(). A subsequent registration for the same T replaces the previous one.

pub fn provide<T>(&mut self, service: Arc<T>) -> &mut Self

where T: ?Sized + Send + Sync + 'static,

Register a pre-built Arc<T>.

Required when registering trait objects, because the concrete type must be erased before storage:

let mut c = Container::new();
c.provide::<dyn Greeter>(Arc::new(Hello));
assert_eq!(c.get::<dyn Greeter>().unwrap().greet(), "hi");

Also usable for concrete types when you already have an Arc.

pub fn register_named<T: Send + Sync + 'static>( &mut self, name: impl Into<String>, service: T, ) -> &mut Self

Register a named concrete service.

Use this when you need multiple instances of the same type (e.g., primary vs. replica database pools).

pub fn provide_named<T>( &mut self, name: impl Into<String>, service: Arc<T>, ) -> &mut Self

where T: ?Sized + Send + Sync + 'static,

Register a pre-built Arc<T> under a string name.

Use for named trait-object registrations.

pub fn get<T>(&self) -> Option<Arc<T>>

where T: ?Sized + 'static, Arc<T>: Clone,

Resolve a service by type.

Works for both concrete types (get::<MyService>()) and trait objects (get::<dyn MyTrait>()). Returns None if no service of that type has been registered.

pub fn get_named<T>(&self, name: &str) -> Option<Arc<T>>

where T: ?Sized + 'static, Arc<T>: Clone,

Resolve a named service by type and name.

Returns None if no service of that type and name has been registered.

pub fn contains<T: ?Sized + 'static>(&self) -> bool

Returns true if a service of type T has been registered (unnamed).

pub fn contains_named<T: ?Sized + 'static>(&self, name: &str) -> bool

Returns true if a named service of type T with name exists.

pub fn len(&self) -> usize

Total number of unnamed registrations.

pub fn is_empty(&self) -> bool

Returns true if no services have been registered.

pub fn into_arc(self) -> Arc<Self>

Seal this container into an Arc<Container> for sharing across threads and handler closures.

Typical usage with App::with_state:

let mut c = Container::new();
// c.register(...);
let app = App::with_state(c.into_arc());

Trait Implementations

impl Default for Container

fn default() -> Self

Returns the “default value” for a type.