cpp enum in class

cpp이랑은 안친한데 크윽 ㅠㅠ

컴파일러나 Cxx 적용 버전의 차이겠지만

$ g++ --version

g++ (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

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g++ 4.6.3 에서는 scope 인식을 하긴 하는데

$ cat enum.cpp #include <iostream> class A { public:         int a;         enum         {                 A_1,                 A_2,                 A_3         }; }; class B { public:         int b;         enum         {                 B_1,                 B_2,                 B_3         }; }; int main() {         A a;         B b;         a.a = B_1;         a.a = A_1;         b.b = A_1;         b.b = B_1;         return 0; }

$ g++ enum.cpp enum.cpp: In function ‘int main()’: enum.cpp:33:8: error: ‘B_1’ was not declared in this scope enum.cpp:34:8: error: ‘A_1’ was not declared in this scope

clang에서는 scope를 조금더 정밀하게 따지는 듯?

$ clang --analyze enum.cpp enum.cpp:33:8: error: use of undeclared identifier 'B_1'         a.a = B_1;               ^ enum.cpp:34:8: error: use of undeclared identifier 'A_1'         a.a = A_1;               ^ enum.cpp:36:8: error: use of undeclared identifier 'A_1'         b.b = A_1;               ^ enum.cpp:37:8: error: use of undeclared identifier 'B_1'         b.b = B_1;               ^ 4 errors generated.

scope만 잡아주면.. public에서 선언한거라 문제없이 되는건가?

$ cat enum.cpp #include <iostream> class A { public:         int a;         enum         {                 A_1,                 A_2,                 A_3         }; }; class B { public:         int b;         enum         {                 B_1,                 B_2,                 B_3         }; }; int main() {         A a;         B b;         a.a = B::B_1;         a.a = A::A_1;         b.b = A::A_1;         b.b = B::B_1;         return 0; }

$ g++ enum.cpp $ clang --analyze enum.cpp

enum 자체에 private를 줘보니..

에러 뿜뿜!

$ cat enum.cpp #include <iostream> class A { public:         int a; private:         enum         {                 A_1,                 A_2,                 A_3         }; }; class B { public:         int b; private:         enum         {                 B_1,                 B_2,                 B_3         }; }; int main() {         A a;         B b;         a.a = B::B_1;         a.a = A::A_1;         b.b = A::A_1;         b.b = B::B_1;         return 0; }

$ g++ enum.cpp enum.cpp: In function ‘int main()’: enum.cpp:25:3: error: ‘B::<anonymous enum> B::B_1’ is private enum.cpp:37:11: error: within this context enum.cpp:11:3: error: ‘A::<anonymous enum> A::A_1’ is private enum.cpp:38:11: error: within this context enum.cpp:11:3: error: ‘A::<anonymous enum> A::A_1’ is private enum.cpp:40:11: error: within this context enum.cpp:25:3: error: ‘B::<anonymous enum> B::B_1’ is private enum.cpp:41:11: error: within this context

$ clang --analyze enum.cpp enum.cpp:37:11: error: 'B_1' is a private member of 'B'         a.a = B::B_1;                  ^ enum.cpp:25:3: note: declared private here                 B_1,                 ^ enum.cpp:38:11: error: 'A_1' is a private member of 'A'         a.a = A::A_1;                  ^ enum.cpp:11:3: note: declared private here                 A_1,                 ^ enum.cpp:40:11: error: 'A_1' is a private member of 'A'         b.b = A::A_1;                  ^ enum.cpp:11:3: note: declared private here                 A_1,                 ^ enum.cpp:41:11: error: 'B_1' is a private member of 'B'         b.b = B::B_1;                  ^ enum.cpp:25:3: note: declared private here                 B_1,                 ^ 4 errors generated.

결론 

public일 경우 당연히(!) 다른 클래스에서도 사용 가능,

private일 때는 당연히(!) 다른 클래스에서는 사용 불가