Code can't find previously defined class

[homer_3]

I have a file that has several class delcarations in it. It looks like

class A : public B
{
public:
  virtual int call (void)
  {
    stuff;
    return -1;
  }
};

class C : public D, private E
{
  stuff;
};

int C::foo(void)
{
 A *req;
 return 0;
}

When I try to compile, at "A *req" I get identifier "req" is undefined. But req isn't the identifier, A is. So it looks like it can't find A. But why wouldn't it find it. It's in the same file.