Struct ResolveContext 

pub struct ResolveContext { /* private fields */ }

The resolution context passed through provider chains.

This struct holds:

• A reference to the typed singleton store
• A reference to the dynamic provider registry (for external types)
• A list of registered destructors (for #[injectable(pre_destruct)] hooks)

Resolution Strategy

When resolve::<T>() is called:

1. If T: Injectable, use T::Provider::provide() (fully static)
2. If T is in the provider registry, use its DynProvider (for external types)
3. Otherwise, return MissingDependency error

Type Safety

The singleton store uses generated typed fields (no Any/TypeId). The provider registry uses TypeId internally but this is never exposed to users — the public API is fully typed.

Implementations

impl ResolveContext

pub fn new( store: Arc<dyn SingletonStore>, registry: Arc<ProviderRegistry>, ) -> ResolveContext

Create a new ResolveContext with the given singleton store and registry.

pub fn from_store(store: Arc<dyn SingletonStore>) -> ResolveContext

Create a ResolveContext with only a store (no dynamic providers).

pub fn store(&self) -> &Arc<dyn SingletonStore>

Get a reference to the underlying singleton store.

pub fn registry(&self) -> &ProviderRegistry

Get a reference to the provider registry.

pub async fn extract<T>(&self) -> Result<T, InjectableError>

where T: Extract + Send + Sync + 'static,

Extract a value using the scope-safe crate::Extract path.

This is the recommended way to resolve a type inside a factory closure or DynProvider::with_ctx. Unlike the old ctx.resolve::<T>(), this respects singleton / transient scope and goes through the full singleton cache machinery.

Example

DynProvider::with_ctx(|ctx| async move {
    let config: Inject<AppConfig> = ctx.extract().await?;
    Ok(Database::connect(&config.db_url).await?)
})

pub async fn clone_from_singleton<T>(&self) -> Result<T, InjectableError>

where T: Injectable + Clone,

Extract an owned singleton value by cloning from the singleton cache.

Called by the generated impl Extract for T where T: Clone for singleton types — this avoids the #[async_trait] macro which has trouble with concrete-type where T: Clone bounds on impl blocks.

pub async fn resolve_external<T>(&self) -> Result<T, InjectableError>

where T: Send + Sync + 'static,

Resolve an external type from the provider registry using the default token.

Use this for types that don’t implement Injectable but have been registered via ContainerBuilder::register("", DynProvider::…).

For named tokens use resolve_external_with_token.

Example

let client = ctx.resolve_external::<reqwest::Client>().await?;

pub async fn resolve_external_with_token<T>( &self, token: &str, ) -> Result<T, InjectableError>

where T: Send + Sync + 'static,

Resolve an external type from the provider registry using an explicit token.

Use this when multiple providers of the same type are registered under different tokens (e.g., "primary" vs "replica" database pools).

Example

let primary: Pool = ctx.resolve_external_with_token("primary").await?;
let replica:  Pool = ctx.resolve_external_with_token("replica").await?;

pub async fn try_resolve_external<T>( &self, ) -> Option<Result<T, InjectableError>>

where T: Send + Sync + 'static,

Try to resolve a type from the registry using the default token.

Returns None if no provider is registered, rather than an error.

pub async fn try_resolve_external_with_token<T>( &self, token: &str, ) -> Option<Result<T, InjectableError>>

where T: Send + Sync + 'static,

Try to resolve a type from the registry using an explicit token.

Returns None if no provider is registered for (T, token).

pub fn register_destructor(&self, instance: Arc<dyn PreDestruct>)

Register a destructor for an instance that implements PreDestruct.

This is called by the generated provider code when #[injectable(has_pre_destruct)] is specified. The destructor will be called during container shutdown.

pub fn register_destructor_with_name( &self, type_name: &'static str, instance: Arc<dyn PreDestruct>, )

Register a destructor with a type name for debugging.

pub async fn run_destructors(&self) -> Result<(), Vec<InjectableError>>

Run all registered pre_destruct hooks in reverse order.

This should be called during container shutdown. Instances are destroyed in reverse construction order (last constructed, first destroyed).

All destructors are called even if some fail (best-effort cleanup). Any errors are collected and returned as InjectableError::ShutdownFailed.

pub async fn destructor_count(&self) -> usize

Returns the number of registered destructors.

Trait Implementations

impl Clone for ResolveContext

fn clone(&self) -> ResolveContext

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ResolveContext

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

Formats the value using the given formatter.