public function dequeue() : \generator
{
while ($this->count() === 0) {
yield;
}
return parent::dequeue();
}
<?php
namespace struct;
//数据结构
//栈
$stack = new \splStack();
$stack->push('one');
//入栈
$stack->push('two');
echo $stack->pop();
//出栈
echo $stack->pop();
//队列
$queue = new \splQueue();
$queue->enqueue('three');
//入队
$queue->enqueue('four');
echo $queue->dequeue();
//出队
echo $queue->dequeue();
//(最小)堆
$heap = new \splMinHeap();
$heap->insert('five');
$heap->insert('six');
echo $heap->extract();
echo $heap->extract();
//固定尺寸的数组
$sarr = new \splFixedArray(10);
$sarr[0] = 'a';
$sarr[8] = 'c';