The implementation of IEnumerable <T> and IEnumerable.GetEnumerator () may not be publicly available, why?

Question

To implement an interface member, the corresponding implementation class member must be publicly available. source: Interfaces (C # Programming Guide)

I know this works if its personal, but I would like to understand why it cannot be publicly available?

Answer 1

When explicitly implemented interface methods are public by default and why you cannot use access modifiers.

Quote from msdn.com:

When an element is explicitly implemented, an instance of the class cannot be accessed, but only through an instance of the interface (which is public by default)

: https://msdn.microsoft.com/en-us/library/aa288461%28v=vs.71%29.aspx

P.S. :

interface MyInterface
{
   void MyMethod();
}

class A : MyInterface  // Implicit implementation
{
   public void MyMethod () { ... }
}

class B: MyInterface   // Explicit implementation
{
   void MyInterface.MyMethod () { ... }
}