### init
    use strict;
    use warnings;
### ampersand variants
    fooFunc (1,2);      ### ok, ampersand optional
    &fooFunc(1,2);      ### ok, apersand optional

    #foneFunc(1,2);     ### NOT ok, called too early
    &foneFunc(1,2);     ### ok, ampersand required

    #fwoFunc(1,2);      ### NOT ok, too early
    &fwoFunc(1,2);      ### ok, ampersand required
    print "\n--------------------------\n";

sub fooFunc {
    if($_[0]){print "fooFunc arg0: ". $_[0] ."\n"}
    if($_[1]){print "fooFunc arg1: ". $_[1] ."\n"}
    print "-------------\n";
}

sub foneFunc() {
    if($_[0]){print "foneFunc arg0: ". $_[0] ."\n"}
    if($_[1]){print "foneFunc arg1: ". $_[1] ."\n"}
    print "-------------\n";
}

sub fwoFunc($$){
    if($_[0]){print "fwoFunc arg0: ". $_[0] ."\n"}
    if($_[1]){print "fwoFunc arg1: ". $_[1] ."\n"}
    print "-------------\n";
}