Initialize a protected static member from a subclass

Question

I want to know if a protected static member can be initialized from a subclass.
For instance,

// head file
class Test
{
protected:
    static int i;
};
class Test2 : public Test{};

//cpp file
#include "headfile.h"
int Test2::i = 1;

As you can see, when I initialize this static member (i), I use the name of the subclass (Test2).
To my surprise, I tested this code with visual studio 2013 and it worked without errors. But if I tried this with Netbeans (gcc11) under Linux, and I got a hint error:
unable to resolve the identifier i
Then I compiled it, error message:
error: ISO C++ does not permit ‘Test::i’ to be defined as ‘Test2::i’ [-fpermissive]

Now, if I change the protected publication for static int iin the class test, the error will disappear.

I got confused ... This is my first time I found two different results with gcc and vs.

Answer 1

++ 14 [class.static.data] §9.4.2/2. :

::.

GCC ( Coliru) . GCC -fpermissive, , , .