1 // RUN: %clang_cc1 -fsyntax-only -verify -pedantic -Wc++11-compat %s
2 //
3 // Tests explicit instantiation of templates.
4 template<typename T, typename U = T> class X0 { };
5
6 namespace N {
7 template<typename T, typename U = T> class X1 { };
8 }
9
10 // Check the syntax of explicit instantiations.
11 template class X0<int, float>;
12 template class X0<int>; // expected-note{{previous}}
13
14 template class N::X1<int>;
15 template class ::N::X1<int, float>;
16
17 using namespace N;
18
19 // Check for some bogus syntax that probably means that the user
20 // wanted to write an explicit specialization, but forgot the '<>'
21 // after 'template'.
22 template class X0<double> { }; // expected-error{{explicit specialization}}
23
24 // Check for explicit instantiations that come after other kinds of
25 // instantiations or declarations.
26 template class X0<int, int>; // expected-error{{duplicate}}
27
28 template<> class X0<char> { }; // expected-note{{previous}}
29 template class X0<char>; // expected-warning{{ignored}}
30
foo(X0<short>)31 void foo(X0<short>) { }
32 template class X0<short>;
33
34 // Check that explicit instantiations actually produce definitions. We
35 // determine whether this happens by placing semantic errors in the
36 // definition of the template we're instantiating.
37 template<typename T> struct X2; // expected-note{{declared here}}
38
39 template struct X2<float>; // expected-error{{undefined template}}
40
41 template<typename T>
42 struct X2 {
43 void f0(T*); // expected-error{{pointer to a reference}}
44 };
45
46 template struct X2<int>; // okay
47 template struct X2<int&>; // expected-note{{in instantiation of}}
48
49 // Check that explicit instantiations instantiate member classes.
50 template<typename T> struct X3 {
51 struct Inner {
52 void f(T*); // expected-error{{pointer to a reference}}
53 };
54 };
55
56 void f1(X3<int&>); // okay, Inner, not instantiated
57
58 template struct X3<int&>; // expected-note{{instantiation}}
59
60 template<typename T> struct X4 {
61 struct Inner {
62 struct VeryInner {
63 void f(T*); // expected-error 2{{pointer to a reference}}
64 };
65 };
66 };
67
68 void f2(X4<int&>); // okay, Inner, not instantiated
69 void f3(X4<int&>::Inner); // okay, Inner::VeryInner, not instantiated
70
71 template struct X4<int&>; // expected-note{{instantiation}}
72 template struct X4<float&>; // expected-note{{instantiation}}
73
74 // Check explicit instantiation of member classes
75 namespace N2 {
76
77 template<typename T>
78 struct X5 {
79 struct Inner1 {
80 void f(T&);
81 };
82
83 struct Inner2 { // expected-note {{here}}
84 struct VeryInner {
85 void g(T*); // expected-error 2{{pointer to a reference}}
86 };
87 };
88 };
89
90 }
91
92 template struct N2::X5<void>::Inner2;
93
94 using namespace N2;
95 template struct X5<int&>::Inner2; // expected-note{{instantiation}}
96
97 void f4(X5<float&>::Inner2);
98 template struct X5<float&>::Inner2; // expected-note{{instantiation}}
99
100 namespace N3 {
101 template struct N2::X5<int>::Inner2; // expected-warning {{explicit instantiation of 'Inner2' not in a namespace enclosing 'N2'}}
102 }
103
104 struct X6 {
105 struct Inner { // expected-note{{here}}
106 void f();
107 };
108 };
109
110 template struct X6::Inner; // expected-error{{non-templated}}
111
112 // PR5559
113 template <typename T>
114 struct Foo;
115
116 template <>
117 struct Foo<int> // expected-note{{header not required for explicitly-specialized}}
118 {
119 template <typename U>
120 struct Bar
121 {};
122 };
123
124 template <> // expected-warning{{extraneous template parameter list}}
125 template <>
126 struct Foo<int>::Bar<void>
127 {};
128
129 namespace N1 {
130
131 template<typename T> struct X7 { }; // expected-note{{here}}
132
133 namespace Inner {
134 template<typename T> struct X8 { };
135 }
136
137 template struct X7<int>;
138 template struct Inner::X8<int>;
139 }
140
141 template<typename T> struct X9 { }; // expected-note{{here}}
142
143 template struct ::N1::Inner::X8<float>;
144
145 namespace N2 {
146 using namespace N1;
147
148 template struct X7<double>; // expected-warning{{must occur in namespace}}
149
150 template struct X9<float>; // expected-warning{{must occur at global scope}}
151 }
152