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 Set

public function toImmVector(): ImmVector<Tv>;

Returns

• ImmVector<Tv> - an ImmVector (integer-indexed) with the values of the current Set.

Examples

This example shows that toImmVector returns an ImmVector containing the Set's values. Mutating the original Set doesn't affect the ImmVector.

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

<<__EntryPoint>>
function basic_usage_main(): void {
  $s = Set {'red', 'green', 'blue', 'yellow'};

  // Get an immutable Vector $v of the values in Set $s
  $immutable_v = $s->toImmVector();

  // Add a color to the original Set $s
  $s->add('purple');

  expects_immutable($immutable_v);
}