return 0 if ref($class) || !defined($class) || !length($class);
- no strict 'refs';
- return 1 if defined ${"${class}::VERSION"} || defined @{"${class}::ISA"};
- foreach my $symbol (keys %{"${class}::"}) {
- next if substr($symbol, -2, 2) eq '::';
- return 1 if defined &{"${class}::${symbol}"};
+ # walk the symbol table tree to avoid autovififying
+ # \*{${main::}{"Foo::"}} == \*main::Foo::
+
+ my $pack = \*::;
+ foreach my $part (split('::', $class)) {
+ return 0 unless exists ${$$pack}{"${part}::"};
+ $pack = \*{${$$pack}{"${part}::"}};
}
+
+ # check for $VERSION or @ISA
+ return 1 if exists ${$$pack}{VERSION}
+ && defined *{${$$pack}{VERSION}}{SCALAR};
+ return 1 if exists ${$$pack}{ISA}
+ && defined *{${$$pack}{ISA}}{ARRAY};
+
+ # check for any method
+ foreach ( keys %{$$pack} ) {
+ next if substr($_, -2, 2) eq '::';
+ return 1 if defined *{${$$pack}{$_}}{CODE};
+ }
+
+ # fail
return 0;
}