think you'd have to give a practical example of real harm being caused by these flag changes.

I don't have such an example.
I do note that, with the demo I provided, you'd be in for a nasty surprise if you omit the second Dump() and go on to pass the perl scalar to an XSub that acts differently when the IsUV flag is set.
But then, of course, that XSub should have been checking SvUOK(sv), not SvISUV(sv).
I do have XSubs that behave differently, based on the UV status. Luckily, they look at SvUOK(sv) and not SvIsUV(sv).

I think I'll restrict this notion of manually reverting flags "for emergency use only" - things like asteroid strikes, extreme geophysical disturbances, alien invasions, etc ;-)

Cheers,
Rob

In reply to Re^4: Reverting the internals of an IV to their original states by syphilis
in thread Reverting the internals of an IV to their original states by syphilis

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.