ToImmVector

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Returns an immutable vector (ImmVector) with the values of the current Map

public function toImmVector(): ImmVector<Tv>;

Returns

• ImmVector<Tv> - an ImmVector that is an immutable copy of the current Map.

Examples

This example shows that toImmVector returns an immutable copy of the Map's values. Mutating the Vector of values doesn't affect the original Map and vice-versa.

function expects_immutable(ImmVector<string> $iv): void {
  \var_dump($iv);
}

<<__EntryPoint>>
function basic_usage_main(): void {
  $m = Map {
    'red' => '#ff0000',
    'green' => '#00ff00',
    'blue' => '#0000ff',
    'yellow' => '#ffff00',
  };

  // Get an immutable Vector of $m's values
  $immutable_v = $m->toImmVector();

  // Add a color to the original Map $m
  $m->add(Pair {'purple', '#663399'});

  expects_immutable($immutable_v);
}