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

You declare the class within the namespace but define it outside the namespace. So the declaration is:

classspace::Aclass

but the definition defines the implementation for:

::Aclass

Namespaces should match for declaration and definition.