6   template<typename T> struct A {  struct
8       B b; // expected-error {{has incomplete type 'test1::A<int>::B'}}
10     B b; // expected-note {{in instantiation of}}
16   template<typename T> struct A {  struct
17     struct B {
20       friend constexpr int operator+(int, C) { return 4; }  in operator +()
22     B b; // expected-note {{in instantiation of}}
29   template<typename T> struct A {  struct
30     struct B {
34     B b;
41   template<typename T> struct A {  struct
42     struct B { // expected-note {{not complete until the closing '}'}}
45     B b; // expected-note {{in instantiation of}}