sub merge {
   if(wantarray) {
      return @_;
   }
   else {
      return join('',@_);
   }
}

##</code><code>##

my %hash = merge(%hash1,%hash2);

##</code><code>##

my @array = merge(@array1,@array2);
my $scalar = merge($scalar1,$scalar2);

# or like the push function (only you have to get the return value)

my @array = merge(@array2,$scalar);