// RUN: %clang_cc1 -fsyntax-only -verify %s struct Base { }; struct Derived : Base { }; // expected-note{{candidate constructor (the implicit copy constructor) not viable}} struct Unrelated { }; struct Derived2 : Base { }; struct Diamond : Derived, Derived2 { }; struct ConvertibleToBaseRef { operator Base&() const; }; struct ConvertibleToDerivedRef { operator Derived&() const; }; struct ConvertibleToBothDerivedRef { operator Derived&(); // expected-note{{candidate function}} operator Derived2&(); // expected-note{{candidate function}} }; struct ConvertibleToIntRef { operator int&(); }; struct ConvertibleToBase { operator Base() const; }; struct ConvertibleToDerived { operator Derived() const; }; struct ConvertibleToBothDerived { operator Derived(); // expected-note{{candidate function}} operator Derived2(); // expected-note{{candidate function}} }; struct ConvertibleToInt { operator int(); }; template<typename T> T create(); // First bullet: lvalue references binding to lvalues (the simple cases). void bind_lvalue_to_lvalue(Base b, Derived d, const Base bc, const Derived dc, Diamond diamond, int i) { // Reference-compatible Base &br1 = b; Base &br2 = d; Derived &dr1 = d; Derived &dr2 = b; // expected-error{{non-const lvalue reference to type 'Derived' cannot bind to a value of unrelated type 'Base'}} Base &br3 = bc; // expected-error{{drops qualifiers}} Base &br4 = dc; // expected-error{{drops qualifiers}} Base &br5 = diamond; // expected-error{{ambiguous conversion from derived class 'Diamond' to base class 'Base':}} int &ir = i; long &lr = i; // expected-error{{non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int'}} } void bind_lvalue_quals(volatile Base b, volatile Derived d, volatile const Base bvc, volatile const Derived dvc, volatile const int ivc) { volatile Base &bvr1 = b; volatile Base &bvr2 = d; volatile Base &bvr3 = bvc; // expected-error{{binding of reference to type 'volatile Base' to a value of type 'const volatile Base' drops qualifiers}} volatile Base &bvr4 = dvc; // expected-error{{binding of reference to type 'volatile Base' to a value of type 'const volatile Derived' drops qualifiers}} volatile int &ir = ivc; // expected-error{{binding of reference to type 'volatile int' to a value of type 'const volatile int' drops qualifiers}} const volatile Base &bcvr1 = b; const volatile Base &bcvr2 = d; } void bind_lvalue_to_rvalue() { Base &br1 = Base(); // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a temporary of type 'Base'}} Base &br2 = Derived(); // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a temporary of type 'Derived'}} const volatile Base &br3 = Base(); // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a temporary of type 'Base'}} const volatile Base &br4 = Derived(); // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a temporary of type 'Derived'}} int &ir = 17; // expected-error{{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}} } void bind_lvalue_to_unrelated(Unrelated ur) { Base &br1 = ur; // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a value of unrelated type 'Unrelated'}} const volatile Base &br2 = ur; // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a value of unrelated type 'Unrelated'}} } void bind_lvalue_to_conv_lvalue() { // Not reference-related, but convertible Base &nbr1 = ConvertibleToBaseRef(); Base &nbr2 = ConvertibleToDerivedRef(); Derived &ndr1 = ConvertibleToDerivedRef(); int &ir = ConvertibleToIntRef(); } void bind_lvalue_to_conv_lvalue_ambig(ConvertibleToBothDerivedRef both) { Derived &dr1 = both; Base &br1 = both; // expected-error{{reference initialization of type 'Base &' with initializer of type 'ConvertibleToBothDerivedRef' is ambiguous}} } struct IntBitfield { int i : 17; // expected-note{{bit-field is declared here}} }; void test_bitfield(IntBitfield ib) { int & ir1 = (ib.i); // expected-error{{non-const reference cannot bind to bit-field 'i'}} } // Second bullet: const lvalue reference binding to an rvalue with // similar type (both of which are class types). void bind_const_lvalue_to_rvalue() { const Base &br1 = create<Base>(); const Base &br2 = create<Derived>(); const Derived &dr1 = create<Base>(); // expected-error{{no viable conversion}} const Base &br3 = create<const Base>(); const Base &br4 = create<const Derived>(); const Base &br5 = create<const volatile Base>(); // expected-error{{binding of reference to type 'const Base' to a value of type 'const volatile Base' drops qualifiers}} const Base &br6 = create<const volatile Derived>(); // expected-error{{binding of reference to type 'const Base' to a value of type 'const volatile Derived' drops qualifiers}} const int &ir = create<int>(); } // Second bullet: const lvalue reference binds to the result of a conversion. void bind_const_lvalue_to_class_conv_temporary() { const Base &br1 = ConvertibleToBase(); const Base &br2 = ConvertibleToDerived(); } void bind_lvalue_to_conv_rvalue_ambig(ConvertibleToBothDerived both) { const Derived &dr1 = both; const Base &br1 = both; // expected-error{{reference initialization of type 'const Base &' with initializer of type 'ConvertibleToBothDerived' is ambiguous}} }