On Mon, 14 Jul 2008 18:28:57 -0500 Jonathan Rockway <[EMAIL PROTECTED]> wrote:
> Considering B is core, there is probably no need for a module to do > this. But, does this always return correct results? Does the > svref_2object call affect the REFCNT? I am too lazy to check, but these > are nice questions for the documentation to answer. If svref_2object > affects its argument, then it's probably best to write a module that > compensates for this behavior. Actually, now I look at it there seems to be more complicated things going on. Originally I tried testing it with just the HASH or ARRAY based object types people tend to use. I thought I'd try out all the reference types, and here's the behaviour I get: A new SCALAR ref has REFCNT 2 A new ARRAY ref has REFCNT 1 A new HASH ref has REFCNT 1 A new CODE ref has REFCNT 2 A new GLOB ref has REFCNT 3 A new Regex ref has REFCNT 1 [see attached program] It seems interesting that a new SCALAR or CODE ref has 2 references already, and a GLOB has 3. I guess the CODE one -might- be explained by its PAD or something, and maybe the GLOB one has more references in the Perl symbol table, but these are pure guesses. I also cannot explain the SCALAR one. This behaviour seems to complicate the idea of simply asserting REFCNT == 1. -- Paul "LeoNerd" Evans [EMAIL PROTECTED] ICQ# 4135350 | Registered Linux# 179460 http://www.leonerd.org.uk/
#!/usr/bin/perl -w
use strict;
use B qw( svref_2object );
my %refs = (
SCALAR => do { \my $var },
ARRAY => [],
HASH => +{},
CODE => sub {},
GLOB => \*SomeNewName,
Regex => qr/foo/,
);
foreach my $type (qw( SCALAR ARRAY HASH CODE GLOB Regex )) {
my $REFCNT = svref_2object($refs{$type})->REFCNT;
printf "A new %6s ref has REFCNT %d\n", $type, $REFCNT;
}
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