Reference TDictionary<K, V>

  TDictionary<K, V> = class(TObject)
  public
    type
    { TDictionary<K, V>.TKeyValue holds a key value pair }
    TKeyValue = class
    public
      { Create a key value pair given a key }
      constructor Create(const Key: K);
      { The key }
      property Key: K read FKey;
      { The value }
      property Value: V read FValue write FValue;
    end;
    { Get the enumerator for the dictionary }
    function GetEnumerator: IEnumerator<TKeyValue>;
  protected
    { Add a new key value pair to the dictionary }
    procedure AddKeyValue(KeyValue: TKeyValue); virtual;
    { Create a new key value pair for a key }
    function CreateKeyValue(const Key: K): TKeyValue; virtual;
    { Destroy a key value pair when it is removed }
    procedure DestroyKeyValue(KeyValue: TKeyValue); virtual;
    { Change the value of an existing key value pair }
    procedure ChangeKeyValue(KeyValue: TKeyValue; Value: V); virtual;
    { Return a default value if no key exists }
    function DefaultValue: V; virtual;
    { When true key values will automatically be created when a value is
      requested if it doesn't exist }
    property AutoKey: Boolean read FAutoKey write FAutoKey;
  public
    { Create the dictionary }
    constructor Create;
    { Clear the dictionary and destroy it }
    destructor Destroy; override;
    { Remove an item by key }
    procedure Remove(const Key: K);
    { Remove all items from the dictionary }
    procedure Clear;
    { Returns true if the key is in the dictionary }
    function KeyExists(const Key: K): Boolean;
    { Used to compare keys }
    property Comparer: TCompare<K> read FComparer write FComparer;
    { Items indexed by integer }
    property Items[Index: Integer]: TKeyValue read GetItem;
    { Keys indexed by integer }
    property Keys[Index: Integer]: K read GetKey;
    { Values indexed by key }
    property Values[const Key: K]: V read GetValue write SetValue; default;
    { Number of key value pairs }
    property Count: Integer read GetCount;
  end;