// PR c++/42844 // { dg-do compile { target c++11 } } struct A // { dg-message "user-provided default constructor" } { int i; A() = default; // { dg-message "not user-provided" } }; struct Base { Base() {} }; struct Derived : Base // { dg-message "user-provided default constructor" } { int i; Derived() = default; // { dg-message "not user-provided" } }; struct Derived2 : Base // { dg-message "user-provided default constructor" } { int i; Derived2() = default; // { dg-message "not user-provided" } Derived2( Derived2 const& ) = default; }; struct Derived3 : Base // { dg-message "user-provided default constructor" } { int i; Derived3( Derived3 const& ) = default; Derived3() = default; // { dg-message "not user-provided" } }; void f() { const A a; // { dg-error "uninitialized const" } const Derived d; // { dg-error "uninitialized const" } const Derived2 d2; // { dg-error "uninitialized const" } const Derived3 d3; // { dg-error "uninitialized const" } }