p5-var.cpp revision b72db8977ed032d6425045d7e9d36e49d9b2d3f8 
1// RUN: %clang_cc1 -fsyntax-only -verify %s
2
3struct Base { };
4struct Derived : Base { }; // expected-note{{candidate constructor (the implicit copy constructor) not viable}}
5struct Unrelated { };
6struct Derived2 : Base { };
7struct Diamond : Derived, Derived2 { };
8
9struct ConvertibleToBaseRef {
10  operator Base&() const;
11};
12
13struct ConvertibleToDerivedRef {
14  operator Derived&() const;
15};
16
17struct ConvertibleToBothDerivedRef {
18  operator Derived&(); // expected-note{{candidate function}}
19  operator Derived2&(); // expected-note{{candidate function}}
20};
21
22struct ConvertibleToIntRef {
23  operator int&();
24};
25
26struct ConvertibleToBase {
27  operator Base() const;
28};
29
30struct ConvertibleToDerived {
31  operator Derived() const;
32};
33
34struct ConvertibleToBothDerived {
35  operator Derived(); // expected-note{{candidate function}}
36  operator Derived2(); // expected-note{{candidate function}}
37};
38
39struct ConvertibleToInt {
40  operator int();
41};
42
43template<typename T> T create();
44
45// First bullet: lvalue references binding to lvalues (the simple cases).
46void 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
62void 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
76void 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
85void 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
90void 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
98void 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
103struct IntBitfield {
104  int i : 17; // expected-note{{bit-field is declared here}}
105};
106
107void 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).
113void 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.
128void bind_const_lvalue_to_class_conv_temporary() {
129  const Base &br1 = ConvertibleToBase();
130  const Base &br2 = ConvertibleToDerived();
131}
132void 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