inheritance from class,defined in th different namespace

Question

I have 2 classes ,defined in the different namespaces :

//--==file1.hpp==--
namespace n1{
class x1 {
//.....
};
};
//--==file2.hpp==--
namespace n2{
class x1: public n1::x1{
//.....
    };
};

//--== file3.hpp ==--
namespace n2 {
 class x2 {
    private:
      n1::x1* data1_;
    public:
      void func(x1* data2) { data1_ = data2; }
  };
};

The compilation of this fails with

error C2440: '=' : cannot convert from `'n2::x1 *' to 'n1::x1 *'`

I can`t understand what could be a problem,Since n2:x1 inherits from n1::x1...? Thank you

Answer 1

Inheritance from one namespace to another namespace class, should not have any compilation error. It is just that, in the sub-class, if you have to call the method of the parent class (which is in another namespace), you should use the complete name (with namespace).

For you reference:

namespace a
{
class A1 {
 public:
    void testA1() {...}
};
}

namespace b
{
class B1: public class a::A1
{
 public:
    void testB1()
        {
          a::A1::testA1();
          ...
        }
};
}

But looks like, the above problem was just been a typo issue, and has been resolved. However, to clarify on the usage, sample code shall help.