At first glance, you may think the following C++ code runs much faster than the equivalent Perl code. You'd be wrong. The Perl code is actually faster. On the Sun Ultra 2, the Perl code runs 10% faster than the C++ code.

   // C++ code                         # Perl code

   wPerlScalar r = 0;                  $r = 0;

   for (int i = 0; i < 100000; ++i)    for ($i = 0; $i < 100_000; ++$i)
   {                                   {
      r = r + i;                         $r = $r + $i;
   }                                   }