1 // { dg-do compile { target c++11 } } 2 3 struct A; 4 5 struct B 6 { 7 constexpr A & operator= (const A &); // { dg-warning "used" "" { target c++14 } } 8 }; 9 10 struct A : B // { dg-error "cannot be overloaded" "" { target c++14 } } 11 { 12 using B::operator=; 13 } a { a = a }; 14