Re^6: Is this DBM::Deep behavior, or something with tie/bless? (ref)

[ysth]

So just fix Data::Compare. The fixes would probably be quite simple. The best fix is to change such things to:

if( ! eval { @$requires; 1 } ) { # Can't be used as an array ref

It is fine to use ref as a Boolean test. Any other uses of ref I simply can't recommend.

Note that the above trick doesn't work for CODE references so you have to resort to one of the second-best methods. I'd use the following:

Wouldn't that give a useless use warning? I would suggest this instead, which also works for CODE.

if( ! eval { \@$requires } ) { # Can't be used as an array ref

Pre-perl 5.10, either has a problem with arrayrefs being able to be dereferenced as pseudo-hashes.

[tye]

Yes, I have an open bug against Data::Diver for issuing warnings about pseudo-hashes due to this.

You are right about the other warnings as well. Unfortunately, your alternative has other problems:

my $foo;
if(  eval { \@$foo }  ) {
    print $foo, $/;
}
__END__
ARRAY(0x34d10)

In the case of CODE ref testing, there is a different problem:

my $foo= "not_a_code_reference";
print "oops!\n"
    if  eval { \&$foo };

Of course, in some situations, one could consider the latter a feature. But mostly I think it would be unwanted.

It is very sad that Perl still doesn't provide decent tools for determine the data type(s) of a reference. It is no wonder nobody gets this right.

[ysth]

Oh, blast, I always forget that strict exception (except when I take advantage of it intentionally).