Struct NativeHashMap<TKey, TValue>

An unordered, expandable associative array.

Implements
Namespace: Unity.Collections
Assembly: Unity.Collections.dll
Syntax
[NativeContainer]
public struct NativeHashMap<TKey, TValue> : INativeDisposable where TKey : struct, IEquatable<TKey> where TValue : struct
Type Parameters
Name Description
TKey

The type of the keys.
TValue

The type of the values.

Constructors

NativeHashMap(int, AllocatorHandle)

Initializes and returns an instance of NativeHashMap.

Declaration
public NativeHashMap(int capacity, AllocatorManager.AllocatorHandle allocator)
Parameters
Type Name Description
int capacity

The number of key-value pairs that should fit in the initial allocation.
AllocatorManager.AllocatorHandle allocator

The allocator to use.

Properties

Capacity

The number of key-value pairs that fit in the current allocation.

Declaration
public int Capacity { get; set; }
Property Value
Type Description
int

The number of key-value pairs that fit in the current allocation.
Exceptions
Type Condition
Exception

Thrown if value is less than the current capacity.

IsCreated

Whether this hash map has been allocated (and not yet deallocated).

Declaration
public bool IsCreated { get; }
Property Value
Type Description
bool

True if this hash map has been allocated (and not yet deallocated).

IsEmpty

Whether this hash map is empty.

Declaration
public bool IsEmpty { get; }
Property Value
Type Description
bool

True if this hash map is empty.

this[TKey]

Gets and sets values by key.

Declaration
public TValue this[TKey key] { get; set; }
Parameters
Type Name Description
TKey key

The key to look up.
Property Value
Type Description
TValue

The value associated with the key.
Remarks

Getting a key that is not present will throw. Setting a key that is not already present will add the key.

Exceptions
Type Condition
ArgumentException

For getting, thrown if the key was not present.

Methods

Add(TKey, TValue)

Adds a new key-value pair.

Declaration
public void Add(TKey key, TValue item)
Parameters
Type Name Description
TKey key

The key to add.
TValue item

The value to add.
Remarks

If the key is already present, this method throws without modifying the hash map.

Exceptions
Type Condition
ArgumentException

Thrown if the key was already present.

AsParallelWriter()

Returns a parallel writer for this hash map.

Declaration
public NativeHashMap<TKey, TValue>.ParallelWriter AsParallelWriter()
Returns
Type Description
NativeHashMap<TKey, TValue>.ParallelWriter

A parallel writer for this hash map.

Clear()

Removes all key-value pairs.

Declaration
public void Clear()
Remarks

Does not change the capacity.

ContainsKey(TKey)

Returns true if a given key is present in this hash map.

Declaration
public bool ContainsKey(TKey key)
Parameters
Type Name Description
TKey key

The key to look up.
Returns
Type Description
bool

True if the key was present.

Count()

The current number of key-value pairs in this hash map.

Declaration
public int Count()
Returns
Type Description
int

The current number of key-value pairs in this hash map.

Dispose()

Releases all resources (memory and safety handles).

Declaration
public void Dispose()

Dispose(JobHandle)

Creates and schedules a job that will dispose this hash map.

Declaration
public JobHandle Dispose(JobHandle inputDeps)
Parameters
Type Name Description
JobHandle inputDeps

A job handle. The newly scheduled job will depend upon this handle.
Returns
Type Description
JobHandle

The handle of a new job that will dispose this hash map.

GetEnumerator()

Returns an enumerator over the key-value pairs of this hash map.

Declaration
public NativeHashMap<TKey, TValue>.Enumerator GetEnumerator()
Returns
Type Description
NativeHashMap<TKey, TValue>.Enumerator

An enumerator over the key-value pairs of this hash map.

GetKeyArray(AllocatorHandle)

Returns an array with a copy of all this hash map's keys (in no particular order).

Declaration
public NativeArray<TKey> GetKeyArray(AllocatorManager.AllocatorHandle allocator)
Parameters
Type Name Description
AllocatorManager.AllocatorHandle allocator

The allocator to use.
Returns
Type Description
NativeArray<TKey>

An array with a copy of all this hash map's keys (in no particular order).

GetKeyValueArrays(AllocatorHandle)

Returns a NativeKeyValueArrays with a copy of all this hash map's keys and values.

Declaration
public NativeKeyValueArrays<TKey, TValue> GetKeyValueArrays(AllocatorManager.AllocatorHandle allocator)
Parameters
Type Name Description
AllocatorManager.AllocatorHandle allocator

The allocator to use.
Returns
Type Description
NativeKeyValueArrays<TKey, TValue>

A NativeKeyValueArrays with a copy of all this hash map's keys and values.
Remarks

The key-value pairs are copied in no particular order. For all i, Values[i] will be the value associated with Keys[i].

GetValueArray(AllocatorHandle)

Returns an array with a copy of all this hash map's values (in no particular order).

Declaration
public NativeArray<TValue> GetValueArray(AllocatorManager.AllocatorHandle allocator)
Parameters
Type Name Description
AllocatorManager.AllocatorHandle allocator

The allocator to use.
Returns
Type Description
NativeArray<TValue>

An array with a copy of all this hash map's values (in no particular order).

Remove(TKey)

Removes a key-value pair.

Declaration
public bool Remove(TKey key)
Parameters
Type Name Description
TKey key

The key to remove.
Returns
Type Description
bool

True if a key-value pair was removed.

TryAdd(TKey, TValue)

Adds a new key-value pair.

Declaration
public bool TryAdd(TKey key, TValue item)
Parameters
Type Name Description
TKey key

The key to add.
TValue item

The value to add.
Returns
Type Description
bool

True if the key-value pair was added.
Remarks

If the key is already present, this method returns false without modifying the hash map.

TryGetValue(TKey, out TValue)

Returns the value associated with a key.

Declaration
public bool TryGetValue(TKey key, out TValue item)
Parameters
Type Name Description
TKey key

The key to look up.
TValue item

Outputs the value associated with the key. Outputs default if the key was not present.
Returns
Type Description
bool

True if the key was present.

Implements

Extension Methods