Struct near_sdk::collections::LookupSet

pub struct LookupSet<T> { /* private fields */ }

A non-iterable implementation of a set that stores its content directly on the storage trie.

This set stores the values under a hash of the set’s prefix and BorshSerialize of the value.

Implementations

impl<T> LookupSet<T>

pub fn new<S>(element_prefix: S) -> Self

where S: IntoStorageKey,

Create a new map. Use element_prefix as a unique prefix for trie keys.

Examples

use near_sdk::collections::LookupSet;
let mut set: LookupSet<u32> = LookupSet::new(b"s");

pub fn insert_raw(&mut self, element_raw: &[u8]) -> bool

Inserts a serialized element into 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 remove_raw(&mut self, element_raw: &[u8]) -> bool

Removes a serialized element from the set. Returns true if the element was present in the set.

impl<T> LookupSet<T>

where T: BorshSerialize,

pub fn contains(&self, element: &T) -> bool

Returns true if the set contains an element.

Examples

use near_sdk::collections::LookupSet;

let mut set: LookupSet<String> = LookupSet::new(b"s");
assert_eq!(set.contains(&"Element".into()), false);

set.insert(&"Element".into());
assert_eq!(set.contains(&"Element".into()), true);

pub fn remove(&mut self, element: &T) -> bool

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

Examples

use near_sdk::collections::LookupSet;

let mut set: LookupSet<String> = LookupSet::new(b"s");
assert_eq!(set.remove(&"Element".into()), false);

set.insert(&"Element".into());
assert_eq!(set.remove(&"Element".into()), true);

pub fn insert(&mut self, element: &T) -> bool

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.

Examples

use near_sdk::collections::LookupSet;

let mut set: LookupSet<String> = LookupSet::new(b"s");
assert_eq!(set.insert(&"Element".into()), true);
assert_eq!(set.insert(&"Element".into()), false);

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

Trait Implementations

impl<T> BorshDeserialize for LookupSet<T>

fn deserialize_reader<R: Read>(reader: &mut R) -> Result<Self, Error>

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.

fn try_from_reader<R>(reader: &mut R) -> Result<Self, Error>

where R: Read,

impl<T> BorshSerialize for LookupSet<T>

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

impl<T> Debug for LookupSet<T>

where T: Debug + BorshSerialize,

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

Formats the value using the given formatter.