(PECL ds >= 1.0.0)
Ds\Set::copy — Returns a shallow copy of the set
此函数没有参数。
Returns a shallow copy of the set.
Example #1 Ds\Set::copy() example
<?php
$a = new \Ds\Set([1, 2, 3]);
$b = $a->copy();
// Updating the copy doesn't affect the original
$b->add(4);
print_r($a);
print_r($b);
?>
以上例程的输出类似于：
Ds\Set Object
(
[0] => 1
[1] => 2
[2] => 3
)
Ds\Set Object
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
)