HH\ImmMap

ImmMap is an immutable Map

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.

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

Construct it with a Traversable:

$a = dict['a' => 1, 'b' => 2];
$fm = new ImmMap($a);

or use the literal syntax

$fm = ImmMap {'a' => 1, 'b' => 2};

Guides

Interface Synopsis

namespace HH;

final class ImmMap implements \ConstMap<Tk, Tv> {...}

Public Methods