For future compatibility, deleting should be safer than setting. 

my $pkg = \%{ $pkg_name . '::' };
delete $pkg->{$_} for grep !/::\z/, keys %$pkg;

[download]

Update: Or even 

my $pkg = \%{ $pkg_name . '::' };
delete @{$pkg}{ grep !/::\z/, keys %$pkg };

[download]

In reply to Re: What is the correct way to clear package? by ikegami
in thread What is the correct way to clear package? by vokbuz

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