Assumed two assemblies (one C# and one C++), C++ refers
to C#. The follwing code compiles and works well under VS
2002! VS 2003 C++ compiler reports the error

"error
2555: 'TestNamespace::ClassB::IInterfaceB.get_Content':
overriding virtual function return type differs and is
not covariant from 'TestNamespace::ClassA::get_Content'"

Explicit implementation of "IInterfaceA.Content" in
ClassA avoids the compiler error.

Two questions:
Why does this error occur in C++ (and with C# not)?
Why does explicit implementation "solve" the problem?

content of C# assembly:
-----------------------
using System;

namespace TestNamespace
{
    public interface IInterfaceA
    {
        string Content
        {
            get;
        }
    }

    public interface IInterfaceB
    {
        int Content
        {
            get;
        }
    }

    public  class ClassA : IInterfaceA
    {
       
//        string IInterfaceA.Content
//        {
//            get { return ""; }
//        }

        public string Content
        {
            get { return ""; }
        }
    }

    public class ClassC : ClassA, IInterfaceB
    {
        int IInterfaceB.Content
        {
            get { return 0; }
        }
    }
}
------------------------

content of C++ assembly:
------------------------
#pragma once

namespace TestNamespace
{

public __gc class ClassB : public ClassA, public
IInterfaceB
{
public:

    __property int IInterfaceB::get_Content()
    {
        return 0;
    }

};

}
------------------------