&reftitle.intro; Efficient data structures for PHP 7, provided as an alternative to the &array;. See this blog post for benchmarks, discussion and frequently asked questions. &reference.ds.setup; &reference.ds.constants; &reference.ds.examples; &reference.ds.ds.collection; &reference.ds.ds.hashable; &reference.ds.ds.sequence; &reference.ds.ds.vector; &reference.ds.ds.deque; &reference.ds.ds.map; &reference.ds.ds.pair; &reference.ds.ds.set; &reference.ds.ds.stack; &reference.ds.ds.queue; &reference.ds.ds.priorityqueue;