// RUN: %clang_cc1 -std=c++11 -verify %s struct B1 { B1(int); // expected-note {{candidate}} }; struct B2 { B2(int); // expected-note {{candidate}} }; struct D1 : B1, B2 { using B1::B1; // expected-note {{inherited here}} using B2::B2; // expected-note {{inherited here}} }; D1 d1(0); // expected-error {{ambiguous}} struct D2 : B1, B2 { using B1::B1; using B2::B2; D2(int); }; D2 d2(0); // ok // The emergent behavior of implicit special members is a bit odd when // inheriting from multiple base classes. namespace default_ctor { struct C; struct D; struct convert_to_D1 { operator D&&(); }; struct convert_to_D2 { operator D&&(); }; struct A { A(); A(C &&); C &operator=(C&&); A(D &&); D &operator=(D&&); // expected-note {{candidate}} A(convert_to_D2); // expected-note {{candidate}} }; struct B { B(); B(C &&); C &operator=(C&&); B(D &&); D &operator=(D&&); // expected-note {{candidate}} B(convert_to_D2); // expected-note {{candidate}} }; struct C : A, B { using A::A; using A::operator=; using B::B; using B::operator=; }; struct D : A, B { using A::A; // expected-note {{inherited here}} using A::operator=; using B::B; // expected-note {{inherited here}} using B::operator=; D(int); D(const D&); D &operator=(const D&); }; C c; void f(C c) { C c2(static_cast(c)); c = static_cast(c); } // D does not declare D(), D(D&&), nor operator=(D&&), so the base class // versions are inherited. // Exception: we implicitly declare a default constructor so that we can // reason about its properties. D d; // ok, implicitly declared void f(D d) { D d2(static_cast(d)); // ok, ignores inherited constructors D d3(convert_to_D1{}); // ok, ignores inherited constructors D d4(convert_to_D2{}); // expected-error {{ambiguous}} d = static_cast(d); // expected-error {{ambiguous}} } struct Y; struct X { X(); X(volatile Y &); // expected-note 3{{inherited constructor cannot be used to copy object}} } x; struct Y : X { using X::X; } volatile y; struct Z : Y { using Y::Y; } volatile z; // expected-note 4{{no known conversion}} expected-note 2{{would lose volatile}} expected-note 3{{requires 0}} expected-note 3{{inherited here}} Z z1(x); // expected-error {{no match}} Z z2(y); // expected-error {{no match}} Z z3(z); // expected-error {{no match}} }