DocumentationHackReferenceClassHH\PairtoImmSet

HH\Pair::toImmSet

Returns an immutable set (ImmSet) with the values of the current Pair

public function toImmSet(): ImmSet<arraykey, mixed>;

Returns

ImmSet<arraykey, mixed> - an ImmSet with the current values of the current Pair.

Examples

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

// This Pair contains 'foo' twice
$p = Pair {'foo', 'foo'};

$imm_set = $p->toImmSet();
var_dump($imm_set);

Output

object(HH\ImmSet)#2 (1) {
  string(3) "foo"
}

This example shows that converting a Pair to an ImmSet will throw a fatal error if the Pair contains a value that's not a string or an int:

$p = Pair {'foo', -1.5};

// Fatal error will be thrown here
$imm_set = $p->toImmSet();

var_dump($imm_set);

Output

Fatal error: Uncaught exception 'InvalidArgumentException' with message 'Only integer values and string values may be used with Sets' in /user-documentation/api-examples/class.Pair/toImmSet/002-runtime-fatal.php:8
Stack trace:
#0 /user-documentation/api-examples/class.Pair/toImmSet/002-runtime-fatal.php(8): HH\Pair->toImmSet()
#1 {main}