php 获取当前文件中的类名

<?php
namespace Demo;
use Think\core;

class Hello{

}
echo '<pre>';
print_r(get_declared_classes());
/**
array(
    [0]=> stdClass
    ...
    [143] => Redis
    [144] => RedisArray
    [145] => RedisCluster
    [146] => RedisException
    [147] => RedisClusterException
    [148] => Demo\Hello
)
*/