обработка исключений

#include <iostream>
using namespace std;
///////////////////////////////////////////
const int SIZE = 2;
//////////////////////////////////////////
template< class Sparrow >
class Queue
{
 private:
  int top,bot,ctr;
  Sparrow arr[SIZE];
 public:
 class full{};
 class empty{};
 Queue () : top(-1), bot(-1), ctr(0)
 { }
 void additem ( Sparrow Val );
  Sparrow dropval ( );
};
///////////////////////////////////////////
template<class Sparrow>
void Queue<Sparrow> :: additem ( Sparrow Val )
{
 ctr++;
 if( ctr > SIZE-1 )
 { ctr--; throw full(); }
 else
 arr[++bot] = Val;
}
//////////////////////////////////////////
template<class Sparrow>
Sparrow Queue<Sparrow> :: dropval( )
{
 ctr--;
 if( ctr < 0 )
 {ctr++; throw empty();}
 else
 {
  if ( top == bot )
  { int z = top; top = 0; bot = 0; return arr[z]; }
  else
  return arr[++top];
 }
}
////////////////////////////////////////////
int main ( int argc, char* argv[] )
{
 
 Queue<float> o1;
 char ans;
 float v1;
 
 while( ans != 'n' )
 {
 
  cout << " Press A to add a value" << endl;
  cout << " Press D to drop a value" << endl;
  cin >> ans;
 
   try
{
  switch( ans )
  {
   case 'a':
   cout << " Enter value: "<< endl;
   cin >> v1;
   o1.additem(v1);
   cout << " Value " << v1 << " added to the queue " << endl;
   break;
   case 'd':
   cout << " Value " << o1.dropval() << " extracted from the queue " << endl;
   break;
  }
}
  catch(Queue<float>::full)
  {
   cout << " Error! Queue is overfilled!";
  }
 
  catch( Queue<float>::empty )
  {
   cout << " Error! Queue is empty! ";
  }
 
  cout << " Continue?(Y/N): " << endl;
  cin >> ans;
 }
 system("PAUSE");
 return 0;
}

#include <iostream>
#include <process.h>
using namespace std;
const int SZ = 100;
template<class R>
class safearray
{
 private:
  R arr[SZ];
 public:
  class full{};
  class empty{};
  R& operator[]( int n )
  {
   if ( n < 0 )
   throw empty();
   else if ( n >= SZ )
    throw full();
    return arr[n];
  }
};
////////////////////////////////////////
int main ( int argc, char* argv[] )
{
 
 
try
{
 safearray<float> o1;
 for ( int j = 0; j < SZ+2; j++ )
{
 o1[j] = j * 10.0;
}
float temp;
for ( int j = 0; j < SZ; j++ )
{
 temp = o1[j];
cout << " Element "<< j << " equal " << temp << endl;
}
}
catch(safearray<float>::full)
{
 cout << " Incorrect index!( Too Big ) " << endl; exit(1);
}
catch(safearray<float>::empty)
{
 cout << " Incorrect index!(Negative) " << endl; exit(1);
}
system("PAUSE");
return 0;
}

    char ans;
    float v1;
 
    while( ans != 'n' )

char ans = '0';