I'm far from expert on Perl internals, but given the way Perl allocates it variables I think that this would necessitate scanning the entire stack and entire heap attempting to find values in memory locations that 'look like' the SV* in question. Besides being rather slow, it is fraught with dangers.

What would you search for? How would you distinguish between four bytes that contain the address of your C++ object, and four bytes that contain a number that coincidentally matches the address of your C++ object?

And what benefit would you get? If the Perl code is going to indirect through a retained SV* and so trap; if you set it to undef, it is still going to indirect through it and die anyway. It might be a less violent death, but there is still no way for the Perl code to reasonably continue.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
RIP PCW It is as I've been saying!(Audio until 20090817)

In reply to Re^3: perl embedded in C++: how to undefine perl objects that are blessed references to C++ objects when the C++ object destructs by BrowserUk
in thread perl embedded in C++: how to undefine perl objects that are blessed references to C++ objects when the C++ object destructs by kingkongrevenge

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.