in reply to Re: Fast Sets of Scalars in Perl
in thread Fast Sets of Scalars in Perl
I was under the same impression that Perl has one instance of undef, and all SVs that refer to undef refer to it. It is singleton. There's no way to form an undef SV other than sv_undef, that I know of. I think there is also a shareable instance of 1 and 0 (sv_yes and sv_no), but the use of these is not as cut and dried. Check perlguts for more information.
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