ToImmSet

:::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 set (ImmSet) based on the values of the current Map

public function toImmSet(): ImmSet<Tv>;

Returns

• ImmSet<Tv> - an ImmSet with the current values of the current Map.

Examples

This example shows that converting a Map to an ImmSet also removes duplicate values:

// This Map contains repetitions of the hex codes for 'red' and 'blue'
$m = Map {
  'red' => '#ff0000',
  'also red' => '#ff0000',
  'green' => '#00ff00',
  'another red' => '#ff0000',
  'blue' => '#0000ff',
  'another blue' => '#0000ff',
  'yellow' => '#ffff00',
};

$imm_set = $m->toImmSet();

\var_dump($imm_set is \HH\ImmSet<_>);
\var_dump($imm_set);