Re^3: The Null Mull (or, when OO needs more O)

[hardburn]

I just ran your code on 5.8.4 i686-Linux with the same result you did. I'm not sure what is going on here--someone with more understanding of the internals is needed. My guess is that undef isn't staying shared like I expected it would.

It does work with taking a reference to undef, but this breaks the transparency I was hoping for:

BEGIN {
    &Internals::SvREADONLY(\undef, 0);
    undef = 42;
    &Internals::SvREADONLY(\undef, 1);
}

my $x = ${ \undef };
print( ((undef) ? 'True' : 'False'), $/);
print( ((defined undef) ? 'True' : 'False'), $/);
print( (($x) ? 'True' : 'False'), $/);
print( ((defined $x) ? 'True' : 'False'), $/);
print $x, $/;

__OUTPUT__
True
True
True
True
42

[dragonchild]

BEGIN {
    &Internals::SvREADONLY(\undef, 0);
    undef = 42;
    &Internals::SvREADONLY(\undef, 1);
}

use constant UNDEF => ${ \undef };

my $x = UNDEF;

Which is probably better because you're commenting that you did something funky with undef. *shrugs*