[Valmont]

#include <iostream>

using namespace std;

//-- const unsigned REFORM_YEAR = 1582;
bool is_leap(const int);
void print_leap_excl_range(int, int);
//-- int main()
{
  int start, end;
  //Boht are leap years, but wont be printed.
  start = 800;
  end = 2008; 
  
  //Printing *closed* range. So (excl)usive start/end.
  print_leap_excl_range(start, end);
  
  system("pause");
  return 0;
}

//------------------------------------------------ bool is_leap(const int yr)
{
  if( yr % 4 ) return false;
  if( yr < REFORM_YEAR ) return true;
  if( yr % 100 ) return true;
  if( yr % 400 ) return false;
  return true;
}

//------------------------------------------------ void print_leap_excl_range(int start, int end)
{
  //Test for "between". So do *not* include passed end year.
  --end;
  do
  {
    //Test for "between". So do *not* include passed start year.
    ++start;    
    if( is_leap(start) )
    {
      cout<<"Leap Year Found: "<<start<<endl;
    }  
  } while(start < end); 
}

You could do it this way too.
QUESTIONS:
1 ) Is it faster or slower or doesn't it matter?
2) Is it better for some reason?
3) Why?
hint: read my signature below.

void print_leap_excl_range(int start, int end)
{
  //Test for "between". So do *not* include passed end year.
  --end;
  while(++start < end)
  {
    if( is_leap(start) )
    {
      cout<<"Leap Year Found: "<<start<<endl;
    }
  }  
}