How to write two nested classes extend the other parent class each other

Hello. I tried to convert the following C# code into C++/CLI.

namespace ConsoleApplication
{
class Class1
{
public class NestedClass1 : Class2
{
}

public class NestedClass2 : Class2.NestedClass2
{
}
}

class Class2
{
public class NestedClass1 : Class1
{
}

public class NestedClass2 : Class1.NestedClass1
{
}
}
}

At first, I supposed the following code, but it was failed to compile. Anyone know how to write it

namespace ConsoleApplication
{
extern ref class Class1;
extern ref class Class2;
extern ref class Class1::NestedClass1; /* error here */
extern ref class Class1::NestedClass2; /* error here */
extern ref class Class2::NestedClass1; /* error here */
extern ref class Class2::NestedClass2; /* error here */

public ref class Class1
{
public:
ref class NestedClass1 : Class2
{
};

ref class NestedClass2 : Class2::NestedClass2
{
};
};

public ref class Class2
{
public:
ref class NestedClass1 : Class1
{
};

ref class NestedClass2 : Class1::NestedClass1
{
};
};
}

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How to write two nested classes extend the other parent class each other

Raffaele Rialdi
Interesting.

class a
class b
class c : public a
class c0 : public b
class d : public b
class d0 : public a

different approach more extensible

Kuphryn
Charles Lee

You can't forward declare nested classes in C++ so you have to define these classes as follows:

namespace ConsoleApplication {
public ref class Class1 {
public:
ref class NestedClass1;
ref class NestedClass2;
};

public ref class Class2 {
public:
ref class NestedClass1;
ref class NestedClass2;
};

ref class Class1::NestedClass1 : Class2 {
};

ref class Class2::NestedClass1 : Class1 {
};

ref class Class1::NestedClass2 : Class2::NestedClass1 {
};

ref class Class2::NestedClass2 : Class1::NestedClass1 {
};
}
Student_I
Unfortunately as you can't forward declare nested classes in C++ there is no way to break the cyclic connection between these declarations.

Chris Foley

Thank you Jonathan. I have to learn C++ more. I have the other related question.

What is the equivalent C++/CLI code for the following C# code.

namespace ConsoleApplication
{
class Class1
{
public class NestedClass1 : Class2
{
}
public void Method(Class2.NestedClass1 p)
{
}
}
class Class2
{
public class NestedClass1 : Class1
{
}
public void Method(Class1.NestedClass1 p)
{
}
}
}

I have no idea about it.

How to write two nested classes extend the other parent class each other

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