Interestingly, reftype only checks the length of ref, which is why it can probably be fooled by "\0".

You are looking at the perl implementation, which isn't quite what i would consider to the canonical implementation. IMO the canonical implementation is the XS one: 

char *
reftype(sv)
    SV * sv
PROTOTYPE: $
CODE:
{
    if (SvMAGICAL(sv))
    mg_get(sv);
    if(!SvROK(sv)) {
    XSRETURN_UNDEF;
    }
    RETVAL = sv_reftype(SvRV(sv),FALSE);
}
OUTPUT:
    RETVAL

[download]

In Data::Dump::Streamer its implemented as 

char *
reftype(sv)
    SV * sv
PROTOTYPE: $
CODE:
{
    if (SvMAGICAL(sv))
    mg_get(sv);
    if(!SvROK(sv)) {
    XSRETURN_NO;
    } else {
        RETVAL = sv_reftype(SvRV(sv),FALSE);
    }
}
OUTPUT:
    RETVAL

[download]

Notice the only difference is the XSRETURN_NO; versus XSRETURN_UNDEF;. With the benefit of experience IMO the use of XSRETURN_UNDEF; was a mistake. I've said as much on p5p a number of times, but without much response. I guess it would be too dangerous a change, which is why im going to be providing patches to implement _reftype() so you can say 

if (_reftype($foo) eq $TYPE) { ... }

[download]

without worrying about warnings. Of course if you don't want to wait, you can always 

use Data::Dump::Streamer qw(reftype);

[download]

And get the more practical implementation Right Now. :-)

---
$world=~s/war/peace/g

In reply to Re^4: Why reftype and blessed are making my life harder than it needs to be (XS/_reftype) by demerphq
in thread Why reftype and blessed are making my life harder than it needs to be by dragonchild

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