// N4606 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf 
#define msg "p277.cpp(130)11.4 Protected member access [class.protected]"
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>


class B {
protected:
int i;
static int j;
};
class D1 : public B {
};
class D2 : public B {
friend void fr(B*,D1*,D2*);
void mem(B*,D1*);
};
void fr(B* pb, D1* p1, D2* p2) {
pb->i = 1; // ill-formed
p1->i = 2; // ill-formed
p2->i = 3; // OK (access through a D2)

p2->B::i = 4; // OK (access through a D2, even though
// naming class is B)
int B::* pmi_B = &B::i; // ill-formed
int B::* pmi_B2 = &D2::i; // OK (type of &D2::i is int B::*)
B::j = 5; // ill-formed (not a friend of naming class B)
D2::j = 6; // OK (because refers to static member)
}
void D2::mem(B* pb, D1* p1) {
pb->i = 1; // ill-formed
p1->i = 2; // ill-formed
i = 3; // OK (access through this)
B::i = 4; // OK (access through this, qualification ignored)
int B::* pmi_B = &B::i; // ill-formed
int B::* pmi_B2 = &D2::i; // OK
j = 5; // OK (because j refers to static member)
B::j = 6; // OK (because B::j refers to static member)
}
void g(B* pb, D1* p1, D2* p2) {
pb->i = 1; // ill-formed
p1->i = 2; // ill-formed
p2->i = 3; // ill-formed
}

int main(){
  std::cout<< msg << std::endl;
  return EXIT_SUCCESS;
}

$ ./cppgl17.sh p277
$ clang++ p277.cpp
p277.cpp:20:5: error: 'i' is a protected member of 'B'
pb->i = 1; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:21:5: error: 'i' is a protected member of 'B'
p1->i = 2; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:26:22: error: 'i' is a protected member of 'B'
int B::* pmi_B = &B::i; // ill-formed
                     ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:28:4: error: 'j' is a protected member of 'B'
B::j = 5; // ill-formed (not a friend of naming class B)
   ^
p277.cpp:11:12: note: declared protected here
static int j;
           ^
p277.cpp:32:5: error: 'i' is a protected member of 'B'
pb->i = 1; // ill-formed
    ^
p277.cpp:10:5: note: can only access this member on an object of type 'D2'
int i;
    ^
p277.cpp:33:5: error: 'i' is a protected member of 'B'
p1->i = 2; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:36:22: error: 'i' is a protected member of 'B'
int B::* pmi_B = &B::i; // ill-formed
                     ^
p277.cpp:10:5: note: must name member using the type of the current context 'D2'
int i;
    ^
p277.cpp:42:5: error: 'i' is a protected member of 'B'
pb->i = 1; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:43:5: error: 'i' is a protected member of 'B'
p1->i = 2; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
p277.cpp:44:5: error: 'i' is a protected member of 'B'
p2->i = 3; // ill-formed
    ^
p277.cpp:10:5: note: declared protected here
int i;
    ^
10 errors generated.

$ g++-7 p277.cpp
p277.cpp: In function 'void fr(B*, D1*, D2*)':
p277.cpp:20:5: error: 'int B::i' is protected within this context
 pb->i = 1; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:21:5: error: 'int B::i' is protected within this context
 p1->i = 2; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:26:22: error: 'int B::i' is protected within this context
 int B::* pmi_B = &B::i; // ill-formed
                      ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:26:22: error: 'int B::i' is protected within this context
 int B::* pmi_B = &B::i; // ill-formed
                      ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp: In member function 'void D2::mem(B*, D1*)':
p277.cpp:32:5: error: 'int B::i' is protected within this context
 pb->i = 1; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:33:5: error: 'int B::i' is protected within this context
 p1->i = 2; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:36:22: error: 'int B::i' is protected within this context
 int B::* pmi_B = &B::i; // ill-formed
                      ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp: In function 'void g(B*, D1*, D2*)':
p277.cpp:42:5: error: 'int B::i' is protected within this context
 pb->i = 1; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:43:5: error: 'int B::i' is protected within this context
 p1->i = 2; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^
p277.cpp:44:5: error: 'int B::i' is protected within this context
 p2->i = 3; // ill-formed
     ^
p277.cpp:10:5: note: declared protected here
 int i;
     ^