Can we have functions inside functions in C++?

Question

I mean something like:

int main() 
{
  void a() 
  {
      // code
  }
  a();

  return 0;
}

Answer 1

Let me post a solution here for C++03 that I consider the cleanest possible.*

#define DECLARE_LAMBDA(NAME, RETURN_TYPE, FUNCTION) \
    struct { RETURN_TYPE operator () FUNCTION } NAME;

...

int main(){
  DECLARE_LAMBDA(demoLambda, void, (){ cout<<"I'm a lambda!"<