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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