way of defining class in a namespace

Question

I defined a class in a namespace in a header as follows

#ifndef _c1_
#define _c1_

namespace classspace
{
    class Aclass;
}

class Aclass
{
    //body
};

         


        

Answer 1

namespace classspace
{
    class Aclass;
}

class Aclass
{
    //body
};

These two classes are two different classes (with same name).

You're using classspace::Aclass which has not defined yet. Add the body in the namespce:

namespace classspace
{

class Aclass
{
    //body
};

}