Struct near_sdk::store::LookupSet

pub struct LookupSet<T, H = Identity> where
    T: BorshSerialize + Ord,
    H: ToKey, { /* private fields */ }

Implementations

impl<T> LookupSet<T, Identity> where
    T: BorshSerialize + Ord, 

pub fn new<S>(prefix: S) -> Self where
    S: IntoStorageKey, 

Initialize new LookupSet with the prefix provided.

This prefix can be anything that implements IntoStorageKey. The prefix is used when storing and looking up values in storage to ensure no collisions with other collections.

impl<T, H> LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey, 

pub fn with_hasher<S>(prefix: S) -> Self where
    S: IntoStorageKey, 

Initialize a LookupSet with a custom hash function.

Example

use near_sdk::store::{LookupSet, key::Keccak256};

let map = LookupSet::<String, Keccak256>::with_hasher(b"m");

pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool where
    T: Borrow<Q>,
    Q: BorshSerialize + ToOwned<Owned = T> + Ord, 

Returns true if the set contains the specified value.

The value may be any borrowed form of the set’s value type, but BorshSerialize, ToOwned<Owned = T> and Ord on the borrowed form must match those for the value type.

pub fn insert(&mut self, value: T) -> bool where
    T: Clone, 

Adds a value to the set.

If the set did not have this value present, true is returned.

If the set did have this value present, false is returned.

pub fn put(&mut self, value: T)

Puts the given value into the set.

This function will not return whether the passed value was already in the set. Use LookupSet::insert if you need that.

pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool where
    T: Borrow<Q>,
    Q: BorshSerialize + ToOwned<Owned = T> + Ord, 

Removes a value from the set. Returns whether the value was present in the set.

The value may be any borrowed form of the set’s value type, but BorshSerialize, ToOwned<Owned = K> and Ord on the borrowed form must match those for the value type.

impl<T, H> LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey, 

pub fn flush(&mut self)

Flushes the intermediate values of the set before this is called when the structure is Droped. This will write all modified values to storage but keep all cached values in memory.

Trait Implementations

impl<T, H> BorshDeserialize for LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey,
    Box<[u8]>: BorshDeserialize, 

fn deserialize(buf: &mut &[u8]) -> Result<Self, Error>

Deserializes this instance from a given slice of bytes. Updates the buffer to point at the remaining bytes.

fn try_from_slice(v: &[u8]) -> Result<Self, Error>

Deserialize this instance from a slice of bytes.

impl<T, H> BorshSerialize for LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey,
    Box<[u8]>: BorshSerialize, 

fn serialize<W: Write>(&self, writer: &mut W) -> Result<(), Error>

fn try_to_vec(&self) -> Result<Vec<u8, Global>, Error>

Serialize this instance into a vector of bytes.

impl<T, H> Debug for LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey, 

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

Formats the value using the given formatter.

impl<T, H> Drop for LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey, 

fn drop(&mut self)

Executes the destructor for this type.

impl<T, H> Extend<T> for LookupSet<T, H> where
    T: BorshSerialize + Ord,
    H: ToKey, 

fn extend<I>(&mut self, iter: I) where
    I: IntoIterator<Item = T>, 

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.