struct A{}; class B: A {}; struct C: A {}; struct D: B, C { D() { B::a = 0; } }; The above code compiles in g++, even though the standard does not allow D access to any member of the private base class A of public base class B.
First reported on StackOverflow: http://stackoverflow.com/questions/23024091/multiple-inheritance-makes-private-member-accessible
(In reply to arm.nahm from comment #0) > The above code compiles in g++, No it doesn't. Please make sure to copy-paste directly from a file you have tested.
markus@x4 /tmp % cat test.ii class A { public: int a; }; class B : private A { }; class C : public A { }; class D : public B, public C { D () { B::a = 0; } }; markus@x4 /tmp % g++ -c test.ii markus@x4 /tmp % clang++ -c test.ii test.ii:17:13: error: cannot cast 'B' to its private base class 'A' D () { B::a = 0; } ^ test.ii:7:11: note: declared private here class B : private A ^~~~~~~~~ test.ii:17:13: error: 'a' is a private member of 'A' D () { B::a = 0; } ^ test.ii:7:11: note: constrained by private inheritance here class B : private A ^~~~~~~~~ test.ii:4:7: note: member is declared here int a; ^ 2 errors generated.
EDG also rejects the code: test.ii(17): error #308: member "A::a" (declared at line 4) is inaccessible D () { B::a = 0; } ^
Unsetting target milestone of open non-regression bug from version of branch being closed.