Struct StateManager 

pub struct StateManager<R> { /* private fields */ }

The state manager.

Implementations

impl StateManager<AsyncOnlyContext>

pub const fn new() -> Self

Available on crate feature async only.

Creates a new StateManager appropriate for asynchronous-only contexts.

Example

use state_department::AsyncState;

static STATE: AsyncState = AsyncState::new();

pub async fn get<T: Send + Sync + 'static>( &self, ) -> StateRef<'_, T, AsyncOnlyContext>

Available on crate feature async only.

Returns a reference to a value stored in the state.

Panics

• If the state has not yet been initialized.
• If the state has been dropped.
• If the state does not contain a value of the requested type.

Example

use state_department::AsyncState;

static STATE: AsyncState = AsyncState::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init_async(async |state| {
    state.insert(Foo { bar: 42 });
})
.await;

let foo = STATE.get::<Foo>().await;

assert_eq!(foo.bar, 42);

pub async fn try_get<T: Send + Sync + 'static>( &self, ) -> Option<StateRef<'_, T, AsyncOnlyContext>>

Available on crate feature async only.

Attempts to get a reference to a value stored in the state.

This function does not panic.

Example

use state_department::AsyncState;

static STATE: AsyncState = AsyncState::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init_async(async |state| {
    state.insert(Foo { bar: 42 });
})
.await;

let foo = STATE.try_get::<Foo>().await;

assert_eq!(foo.unwrap().bar, 42);

let str = STATE.try_get::<String>().await;

assert!(str.is_none());

impl<R> StateManager<R>

pub fn init<F>(&self, init: F) -> StateLifetime<R>

where F: FnOnce(&mut StateRegistry<R>),

Initializes the StateManager, giving you an entrypoint for populating the state with your desired values.

Panics

• If the state has already been initialized.

Example

use state_department::State;

static STATE: State = State::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init(|state| {
    state.insert(Foo { bar: 42 });
});

assert_eq!(STATE.get::<Foo>().bar, 42);

pub fn try_init<E, F>(&self, init: F) -> Option<Result<StateLifetime<R>, E>>

where F: FnOnce(&mut StateRegistry<R>) -> Result<(), E>,

Initializes the StateManager, giving you a fallible entrypoint for populating the state with your desired values.

Returns None if the StateManager is already initialized.

Example

use state_department::State;

static STATE: State = State::new();

let lifetime = STATE.try_init(|state| {
    Err("oh no!")
});

assert!(lifetime.unwrap().is_err());

pub async fn init_async<F>(&self, init: F) -> StateLifetime<R>

where F: AsyncFnOnce(&mut StateRegistry<R>),

Initializes the StateManager asynchronously, giving you an entrypoint for populating the state with your desired values in an asynchronous context.

Panics

• If the state has already been initialized.

Example

use state_department::State;

static STATE: State = State::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init_async(async |state| {
    state.insert(Foo { bar: 42 });
})
.await;

assert_eq!(STATE.get::<Foo>().bar, 42);

pub async fn try_init_async<E, F>( &self, init: F, ) -> Option<Result<StateLifetime<R>, E>>

where F: AsyncFnOnce(&mut StateRegistry<R>) -> Result<(), E>,

Initializes the StateManager asynchronously, giving you a fallible entrypoint for populating the state with your desired values in an asynchronous context.

Returns None if the StateManager is already initialized.

Example

use state_department::State;

static STATE: State = State::new();

let lifetime = STATE.try_init_async(async |state| {
    Err("oh no!")
});

assert!(lifetime.await.unwrap().is_err());

impl StateManager<AnyContext>

pub const fn new() -> Self

Creates a new StateManager appropriate for both synchronous and asynchronous contexts.

Example

use state_department::State;

static STATE: State = State::new();

pub fn get<T: Send + Sync + 'static>(&self) -> StateRef<'_, T, AnyContext>

Returns a reference to a value stored in the state.

Panics

• If the state has not yet been initialized.
• If the state has been dropped.
• If the state does not contain a value of the requested type.

Example

use state_department::State;

static STATE: State = State::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init(|state| {
    state.insert(Foo { bar: 42 });
});

let foo = STATE.get::<Foo>();

assert_eq!(foo.bar, 42);

pub fn try_get<T: Send + Sync + 'static>( &self, ) -> Option<StateRef<'_, T, AnyContext>>

Attempts to get a reference to a value stored in the state.

This function does not panic.

Example

use state_department::State;

static STATE: State = State::new();

struct Foo {
    bar: i32
}

let _lifetime = STATE.init(|state| {
    state.insert(Foo { bar: 42 });
});

let foo = STATE.try_get::<Foo>();

assert_eq!(foo.unwrap().bar, 42);

let str = STATE.try_get::<String>();

assert!(str.is_none());

Trait Implementations

impl Default for StateManager<AnyContext>

fn default() -> Self

Returns the “default value” for a type.

impl Default for StateManager<AsyncOnlyContext>

Available on crate feature async only.

fn default() -> Self

Returns the “default value” for a type.

impl<R> Drop for StateManager<R>

fn drop(&mut self)

Executes the destructor for this type.

impl<R> Sync for StateManager<R>