It's a very wide spread myth that objects are blessed references. In fact, they are references to blessed variables. The difference? The thing that is blessed.

I agree that the syntax of bless is misleading. But if you bless \$foo, it is $foo that is actually blessed. This means that you can choose to return \$foo; and it'll still work, even though the scalar assigned for the second reference you're creating is an entirely different one. It's not the reference, but $foo that is blessed.

@_ is an array of aliases. These are aliases for the variables used in the call. When such a value/variable is mutable, the element in @_ is automatically as mutable, because it's the same thing. This is a danger with using any element of @_ directly, not just when they're overloaded, and not just with bless. Even assignment to one of the elements is dangerous. The lesson is simple: if you want to change something without changing it, copy and change the copy, so the original stays intact.

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }

In reply to Re: A warning about overloading assignment methods by Juerd
in thread A warning about overloading assignment methods by diotalevi

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.