package Struct::Stuff;

use Exporter;

our @ISA = qw(Exporter);
our @EXPORT_OK = qw(
    %Struct_Dispatch
);

my %Struct_Dispatch = (
    A => \&__PACKAGE__::getAStruct,
    B => \&__PACKAGE__::getBStruct,
# And so on ...
);

sub getAStruct {
}

sub getBStruct {
}

-------

# In your main program ...

use Struct::Stuff qw(%Struct_Dispatch);

# Later ...

foreach my $type (keys %Struct_Dispatch)
{
    print "Doing '$type'\n";
    my $val = $Struct_Dispatch{$type}->();
    print "\tReturns '$val'\n";
}