abusing exceptions

hi all,

this is my first post here.

i was wondering about using use exception handling as a non local goto
so i can implement tail calls, but the result is very slow with msvc
7.1, release build.

can anybody tell me why, whether this is a blind alley, and how to speed
things up if it isn't?

also, if anybody has some resources on implementing tail calls in C++,
i'd be very interested.

cheers
jono
day-one.com

code follows:
====================================================================================

#include <iostream>

enum{SZ=1000};

using std::ostream;
using std::cout;

struct Continuation
{
   Continuation(int cont)
       :cont_(cont)
       {}

   int cont_;
};

ostream &tail_call(ostream &os, int &i)
{
   os << i++ << ' ';
   if(i < SZ)
   {
       throw Continuation(i);
   }
   else
   {
       // do nothing
   }
   return os;
}

ostream &tail_call_0(ostream &os)
{
   int i = 0;
   while(true)
   {
       try
       {
           tail_call(os, i);
       }
       catch(Continuation c)
       {
           i = c.cont_;
           continue;
       }
       break;
   }
   return os;
}

int main(int argc, char* argv[])
{
   tail_call_0(cout);

   return 0;
}

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