1 // RUN: %clang_cc1 -fsyntax-only -verify %s
2
3 struct Base { };
4 struct Derived : Base { }; // expected-note{{candidate constructor (the implicit copy constructor) not viable}}
5 struct Unrelated { };
6 struct Derived2 : Base { };
7 struct Diamond : Derived, Derived2 { };
8
9 struct ConvertibleToBaseRef {
10 operator Base&() const;
11 };
12
13 struct ConvertibleToDerivedRef {
14 operator Derived&() const;
15 };
16
17 struct ConvertibleToBothDerivedRef {
18 operator Derived&(); // expected-note{{candidate function}}
19 operator Derived2&(); // expected-note{{candidate function}}
20 };
21
22 struct ConvertibleToIntRef {
23 operator int&();
24 };
25
26 struct ConvertibleToBase {
27 operator Base() const;
28 };
29
30 struct ConvertibleToDerived {
31 operator Derived() const;
32 };
33
34 struct ConvertibleToBothDerived {
35 operator Derived(); // expected-note{{candidate function}}
36 operator Derived2(); // expected-note{{candidate function}}
37 };
38
39 struct ConvertibleToInt {
40 operator int();
41 };
42
43 template<typename T> T create();
44
45 // First bullet: lvalue references binding to lvalues (the simple cases).
bind_lvalue_to_lvalue(Base b,Derived d,const Base bc,const Derived dc,Diamond diamond,int i)46 void bind_lvalue_to_lvalue(Base b, Derived d,
47 const Base bc, const Derived dc,
48 Diamond diamond,
49 int i) {
50 // Reference-compatible
51 Base &br1 = b;
52 Base &br2 = d;
53 Derived &dr1 = d;
54 Derived &dr2 = b; // expected-error{{non-const lvalue reference to type 'Derived' cannot bind to a value of unrelated type 'Base'}}
55 Base &br3 = bc; // expected-error{{drops qualifiers}}
56 Base &br4 = dc; // expected-error{{drops qualifiers}}
57 Base &br5 = diamond; // expected-error{{ambiguous conversion from derived class 'Diamond' to base class 'Base':}}
58 int &ir = i;
59 long &lr = i; // expected-error{{non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int'}}
60 }
61
bind_lvalue_quals(volatile Base b,volatile Derived d,volatile const Base bvc,volatile const Derived dvc,volatile const int ivc)62 void bind_lvalue_quals(volatile Base b, volatile Derived d,
63 volatile const Base bvc, volatile const Derived dvc,
64 volatile const int ivc) {
65 volatile Base &bvr1 = b;
66 volatile Base &bvr2 = d;
67 volatile Base &bvr3 = bvc; // expected-error{{binding of reference to type 'volatile Base' to a value of type 'const volatile Base' drops qualifiers}}
68 volatile Base &bvr4 = dvc; // expected-error{{binding of reference to type 'volatile Base' to a value of type 'const volatile Derived' drops qualifiers}}
69
70 volatile int &ir = ivc; // expected-error{{binding of reference to type 'volatile int' to a value of type 'const volatile int' drops qualifiers}}
71
72 const volatile Base &bcvr1 = b;
73 const volatile Base &bcvr2 = d;
74 }
75
bind_lvalue_to_rvalue()76 void bind_lvalue_to_rvalue() {
77 Base &br1 = Base(); // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a temporary of type 'Base'}}
78 Base &br2 = Derived(); // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a temporary of type 'Derived'}}
79 const volatile Base &br3 = Base(); // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a temporary of type 'Base'}}
80 const volatile Base &br4 = Derived(); // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a temporary of type 'Derived'}}
81
82 int &ir = 17; // expected-error{{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
83 }
84
bind_lvalue_to_unrelated(Unrelated ur)85 void bind_lvalue_to_unrelated(Unrelated ur) {
86 Base &br1 = ur; // expected-error{{non-const lvalue reference to type 'Base' cannot bind to a value of unrelated type 'Unrelated'}}
87 const volatile Base &br2 = ur; // expected-error{{volatile lvalue reference to type 'const volatile Base' cannot bind to a value of unrelated type 'Unrelated'}}
88 }
89
bind_lvalue_to_conv_lvalue()90 void bind_lvalue_to_conv_lvalue() {
91 // Not reference-related, but convertible
92 Base &nbr1 = ConvertibleToBaseRef();
93 Base &nbr2 = ConvertibleToDerivedRef();
94 Derived &ndr1 = ConvertibleToDerivedRef();
95 int &ir = ConvertibleToIntRef();
96 }
97
bind_lvalue_to_conv_lvalue_ambig(ConvertibleToBothDerivedRef both)98 void bind_lvalue_to_conv_lvalue_ambig(ConvertibleToBothDerivedRef both) {
99 Derived &dr1 = both;
100 Base &br1 = both; // expected-error{{reference initialization of type 'Base &' with initializer of type 'ConvertibleToBothDerivedRef' is ambiguous}}
101 }
102
103 struct IntBitfield {
104 int i : 17; // expected-note{{bit-field is declared here}}
105 };
106
test_bitfield(IntBitfield ib)107 void test_bitfield(IntBitfield ib) {
108 int & ir1 = (ib.i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
109 }
110
111 // Second bullet: const lvalue reference binding to an rvalue with
112 // similar type (both of which are class types).
bind_const_lvalue_to_rvalue()113 void bind_const_lvalue_to_rvalue() {
114 const Base &br1 = create<Base>();
115 const Base &br2 = create<Derived>();
116 const Derived &dr1 = create<Base>(); // expected-error{{no viable conversion}}
117
118 const Base &br3 = create<const Base>();
119 const Base &br4 = create<const Derived>();
120
121 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}}
122 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}}
123
124 const int &ir = create<int>();
125 }
126
127 // Second bullet: const lvalue reference binds to the result of a conversion.
bind_const_lvalue_to_class_conv_temporary()128 void bind_const_lvalue_to_class_conv_temporary() {
129 const Base &br1 = ConvertibleToBase();
130 const Base &br2 = ConvertibleToDerived();
131 }
bind_lvalue_to_conv_rvalue_ambig(ConvertibleToBothDerived both)132 void bind_lvalue_to_conv_rvalue_ambig(ConvertibleToBothDerived both) {
133 const Derived &dr1 = both;
134 const Base &br1 = both; // expected-error{{reference initialization of type 'const Base &' with initializer of type 'ConvertibleToBothDerived' is ambiguous}}
135 }
136