pub struct Item<T> { /* private fields */ }
Expand description

Item stores one typed item at the given key. This is an analog of Singleton. It functions the same way as Path does but doesn’t use a Vec and thus has a const fn constructor.

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impl<T> Item<T>

pub const fn new(storage_key: &'static str) -> Item<T>

Creates a new Item with the given storage key. This is a const fn only suitable when you have a static string slice.

pub fn new_dyn(storage_key: impl Into<Namespace>) -> Item<T>

Creates a new Item with the given storage key. Use this if you might need to handle a dynamic string. Otherwise, you might prefer Item::new.

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impl<T> Item<T>where T: Serialize + DeserializeOwned,

pub fn as_slice(&self) -> &[u8]

pub fn save(&self, store: &mut dyn Storage, data: &T) -> Result<(), StdError>

save will serialize the model and store, returns an error on serialization issues

pub fn remove(&self, store: &mut dyn Storage)

pub fn load(&self, store: &dyn Storage) -> Result<T, StdError>

load will return an error if no data is set at the given key, or on parse error

pub fn may_load(&self, store: &dyn Storage) -> Result<Option<T>, StdError>

may_load will parse the data stored at the key if present, returns Ok(None) if no data there. returns an error on issues parsing

pub fn exists(&self, store: &dyn Storage) -> bool

Returns true if data is stored at the key, false otherwise.

pub fn update<A, E>(&self, store: &mut dyn Storage, action: A) -> Result<T, E>where A: FnOnce(T) -> Result<T, E>, E: From<StdError>,

Loads the data, perform the specified action, and store the result in the database. This is shorthand for some common sequences, which may be useful.

It assumes, that data was initialized before, and if it doesn’t exist, Err(StdError::NotFound) is returned.

pub fn query<Q>( &self, querier: &QuerierWrapper<'_, Q>, remote_contract: Addr ) -> Result<T, StdError>where Q: CustomQuery,

If you import the proper Item from the remote contract, this will let you read the data from a remote contract in a type-safe way using WasmQuery::RawQuery.

Note that we expect an Item to be set, and error if there is no data there

Auto Trait Implementations§

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impl<T> RefUnwindSafe for Item<T>where T: RefUnwindSafe,

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impl<T> Send for Item<T>where T: Send,

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impl<T> Sync for Item<T>where T: Sync,

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impl<T> Unpin for Item<T>where T: Unpin,

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impl<T> UnwindSafe for Item<T>where T: UnwindSafe,

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<U> As for U

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fn as_<T>(self) -> Twhere T: CastFrom<U>,

Casts self to type T. The semantics of numeric casting with the as operator are followed, so <T as As>::as_::<U> can be used in the same way as T as U for numeric conversions. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

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fn vzip(self) -> V