Let class only contain value type fields

Question

What I want to achieve:

A container which contains a bunches of value type fields.

The container has the following characteristics

1. Acts like POD.
2. Mutable
3. Could be copied by value.
4. Fields of the container will keep growing in the future.

For letting it could be copied, my attempt is using MemberwiseClone() which would shallow copy the container.

So a class containing only value type fields might work, but MemberwiseClone() could be broken once the class contains a reference type while MemberwiseClone() copy the reference.

My intent is to prevent inexperienced developers from accidentally breaking the system.

Expected answer:

1. Some kind of attribute node [AllowOnlyValueTypeFields] on a class to allow the compiler to check it.

   [AllowOnlyValueTypeFields]
   class foo {
       int[] bar; // beep! compiled failed.
   }
   

2. Maybe... a design pattern might solve it?

Current workaround:

1. A unit test using reflection and check every field of the container.
2. A "rule" about not using reference type in this container and soon become forgotten.

Search keywords:

1. C# field property only value type
2. C# field property allow only value type
3. C# force only value type field stackoverflow

None of the above got meaningful results.

Any suggestion is appreciated.