Struct SetHandler 

pub struct SetHandler<T>
where
    T: Storable + StorageKey + Hash + Eq + Clone,
{
    values: VecHandler<T>,
    positions: Mapping<T, u32>,
    base_slot: U256,
    address: Address,
}

Type-safe handler for accessing Set<T> in storage.

Provides the OZ storage operations but following the naming convention of HashSet:

Method	OZ equivalent
insert()	add()
remove()	remove()
contains()	contains()
len()	length()
at()	at()
read()	values()
read_range()	values_range()

Also implements Handler<Set<T>> for bulk operations:

• read: Load all elements as Set<T>
• write: Replace entire set
• delete: Remove all elements

Fields

values: VecHandler<T>

Handler for the values vector (stores actual elements).

positions: Mapping<T, u32>

Handler for the positions mapping (value -> 1-indexed position).

base_slot: U256

The base slot for the set.

address: Address

Contract address.

Implementations

impl<T> SetHandler<T>

where T: Storable + StorageKey + Hash + Eq + Clone,

pub fn new(base_slot: U256, address: Address) -> Self

Creates a new handler for the set at the given base slot.

• base_slot: Used as the Vec’s length slot
• base_slot + 1: Used as the Mapping’s base slot

pub fn base_slot(&self) -> U256

Returns the base storage slot for this set.

pub fn len(&self) -> Result<usize>

Returns the number of elements in the set.

pub fn is_empty(&self) -> Result<bool>

Returns whether the set is empty.

pub fn contains(&self, value: &T) -> Result<bool>

where T: StorageKey + Hash + Eq + Clone,

Returns true if the value is in the set.

pub fn insert(&mut self, value: T) -> Result<bool>

where T: StorageKey + Hash + Eq + Clone, T::Handler: Handler<T>,

Inserts a value into the set.

Returns true if the value was inserted (not already present). Returns false if the value was already in the set.

pub fn remove(&mut self, value: &T) -> Result<bool>

where T: StorageKey + Hash + Eq + Clone, T::Handler: Handler<T>,

Removes a value from the set.

Returns true if the value was removed. Otherwise, returns false.

pub fn at(&self, index: usize) -> Result<Option<T>>

where T::Handler: Handler<T>,

Returns the value at the given index with bounds checking.

Returns

• If the SLOAD to read the length fails, returns an error.
• If the index is OOB, returns Ok(None).
• Otherwise, returns Ok(Some(T)).

pub fn read_range(&self, start: usize, end: usize) -> Result<Vec<T>>

where T::Handler: Handler<T>,

Reads a range of values from the set.

This is a partial version of read() for when you only need a subset.

Trait Implementations

impl<T> Clone for SetHandler<T>

where T: Storable + StorageKey + Hash + Eq + Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for SetHandler<T>

where T: Storable + StorageKey + Hash + Eq + Clone,

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

Formats the value using the given formatter.

impl<T> Handler<Set<T>> for SetHandler<T>

where T: Storable + StorageKey + Hash + Eq + Clone, T::Handler: Handler<T>,

fn read(&self) -> Result<Set<T>>

Reads all elements from storage as a Set<T>.

The returned Set preserves storage order: set[i] == handler.at(i).

fn write(&mut self, value: Set<T>) -> Result<()>

Replaces the entire set with new contents.

The input Set is deduplicated by the From<Vec<T>> conversion.

fn delete(&mut self) -> Result<()>

Deletes all elements from the set.

Clears both the values array and all position entries.

fn t_read(&self) -> Result<Set<T>>

Reads the value from storage.

fn t_write(&mut self, _value: Set<T>) -> Result<()>

Writes the value to storage.

fn t_delete(&mut self) -> Result<()>

Deletes the value from storage (sets to zero).

impl<T> Index<usize> for SetHandler<T>

where T: Storable + StorageKey + Hash + Eq + Clone,

fn index(&self, index: usize) -> &Self::Output

Returns a reference to the cached handler for the given index (unchecked).

WARNING: Does not check bounds. Caller must ensure that the index is valid. For checked access use .at(index) instead.

type Output = <T as StorableType>::Handler

The returned type after indexing.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 280 bytes