tobyink has asked for the wisdom of the Perl Monks concerning the following question:

Try this on an old version of Perl (before 5.17) and a newer one (5.18 or above):

perl -MHTTP::Tiny -e'my $class = q(::HTTP::Tiny); $class->new'

Was this change documented anywhere?

Replies are listed 'Best First'.
Re: Change to package name handling in Perl 5.18?
by haukex (Archbishop) on Sep 15, 2020 at 20:30 UTC
    ./Porting/ --target=miniperl --start=v5.16.3 --end=v5.18.0 --expect-fail -e 'sub foo::new {} "::foo"->new'
    commit 7156e69abfd37267e85105c6ec0c449ce4e41523
    Author: Father Chrysostomos <>
    Date:   Thu Sep 20 08:56:38 2012 -0700
        [perl #105922] Allow any string before ->meth
        The rules for filtering out what do not look like package names are
        not logical and disallow valid things like "::main", while allowing
        This commit simply lets any non-empty string be used as a package
        name.  If it is a typo, you’ll get an error anyway.  This allows
        autobox-style calls like "3foo"->CORE::uc, or even "3foo"->uc if you
        set up @ISA first.
        I made an exception for the empty string because it messes up caches
        somehow and causes subsequent method calls all to be called on the
        main package.  I haven’t looked into that yet.  I don’t know whether
        it’s worth it.
        The changes to the tests in cpan/Test-Simple have been submit-
        ted upstream.

    Mentioned in perl5180delta:

    Class method calls are now allowed on any string, and not just strings beginning with an alphanumeric character. [perl #105922]

      Ah. I should have been searching for "class" instead of "package". Thanks.