HH\ImmSet

ImmSet is an immutable, ordered set-style collection

HHVM provides a native implementation for this class. The PHP class definition below is not actually used at run time; it is simply provided for the typechecker and for developer reference.

An ImmSet cannot be mutated. No elements can be added or removed from it, nor can elements be overwritten using assignment (i.e. $s[$k] = $v is not allowed).

Construct it with a Traversable:

$a = array(1, 2);
$s = new ImmSet($a);

or use the literal syntax:

$s = ImmSet {1, 2};

Interface Synopsis

namespace HH {
class ImmSet implements ConstSet {...}
}