Why do i get uncaught exception and the program exits?

[hype261]

If I had to make a guess on why exceptions don't support implicit conversions is because it would be very difficult to do.

Implicit conversions for functions are realitively easy thing for a compiler to do. This function needs a Class A, but you gave it Class B, but A can be constructed from B. Now consider the following code example.

class Error
{
public:
     Error(string c){cout << c;};
};

void c()
{
     throw string("HELP");
}

void b()
{
     c();
}

void a()
{
     b();
}

int main()
{
     try
     {
          a();
     }
     catch(Error err)
     {
     }
}

In this situation the compilier is going to have to go three functions deep to see you are going to throw a string and then do the implicit conversion. This example is really simple, consider what would happen if this was a real application. The compiler could be 50 functions deep across multiple source files.