# First example; nothing gets assigned to @array;
my @array;
sub testthis {
    @_ = qw/This that and the other/;
}
testthis ( @array );

# Second example; nothing gets assigned to @array1 or @array2.
# But no compiletime errors are generated either:
my $condition = int rand 2;
sub testthis {
    @_ = qw/This that and the other/;
}
my ( @array1, @array2 );
testthis( $condition ? @array1 : @array2 );