string - Perl 5 何时获得 Copy-On-Write 字符串？

Question

我知道 Perl 5 现在有 COW 字符串，但我不记得它们是什么时候实现的。

Answer 1

似乎是 Perl 5.20.0 :

Perl has a new copy-on-write mechanism that avoids the need to copy the internal string buffer when assigning from one scalar to another. This makes copying large strings appear much faster. Modifying one of the two (or more) strings after an assignment will force a copy internally. This makes it unnecessary to pass strings by reference for efficiency.