warn $ref in 5.14

[bbrtj]

Since 5.14.0, warn can be used on any reference, and it preserves these references, so it's possible to get more info about them in __WARN__ sig handlers. Before that, they were stringified during warn call. For die this change happened much earlier, but I don't know when exactly. This may be worth noting, as it's pretty hard to find in perldelta.

https://perldoc.perl.org/perl5140delta#Exception-Handling

[choroba]

Interesting. I tried to add the following test:

sub My::Warn::value { 42 }
my $out;
my $w = bless {}, "My::Warn";
local $SIG{__WARN__} = sub { $out = $w->value };
warn $w;
is $out, 42;

But it doesn't fail in 5.012, 5.010, nor 5.008. I probably didn't understand the description correctly, can you enlighten me?

[bbrtj]

Sure, here is your case but slightly modified:

sub My::Warn::value { 42 }
my $out;
local $SIG{__WARN__} = sub { $out = shift->value };
warn bless {}, "My::Warn";
print $out == 42;

Works on 5.14, but fails on 5.12 with error: ERROR: Can't locate object method "value" via package "My::Warn=HASH(0x556b85dcab30)

[choroba]

Of course, I'm stupid, sorry. 🤦🏽

[choroba]

Fixed in #64