When I tested eval, it did invoke overload methods. Here's the test (see also Re^4: Reference assessment techniques and how they fail for a longer version for code refs):
use strict;
use warnings;
use Test::More 'tests' => 4;
use Scalar::Util qw( blessed reftype );
my $side_effect = 0;
package OverloadHash;
use overload '%{}' => sub { $side_effect = 1; {} };
package main;
sub is_hash_eval {
no warnings qw( void uninitialized );
return '' ne ref $_[0] && eval { %{$_[0]}; 1 };
}
sub is_hash_util {
my $suspected_hash = shift;
return 0 if '' eq ref $suspected_hash;
return 1 if 'HASH' eq reftype $suspected_hash;
if ( blessed $suspected_hash
&& overload::Method( $suspected_hash, '%{}' ) ) {
return 1;
}
return 0;
}
check_method( \&is_hash_util, 'utils' );
check_method( \&is_hash_eval, 'eval' );
sub check_method {
my ( $tester, $name ) = @_;
$side_effect = 0;
my $overhash = bless {}, 'OverloadHash';
ok( $tester->( $overhash ), "$name: overloaded reference" );
# this test fails for the eval method
ok( ! $side_effect, "$name: no side effect" );
}
I agree that the best solution to all this would be something sweet in Scalar::Util. I trust it to stay up to date, and it's the right place for it.