templates.cpp revision cd8ab51a44e80625d84126780b0d85a7732e25af 
1// RUN: %clang_cc1 -fsyntax-only -std=c++11 -Winvalid-noreturn %s -verify
2
3template<typename T>
4void test_attributes() {
5  // FIXME: GCC accepts [[gnu::noreturn]] here.
6  auto nrl = []() [[gnu::noreturn]] {}; // expected-warning{{attribute 'noreturn' ignored}}
7}
8
9template void test_attributes<int>();
10
11template<typename T>
12void call_with_zero() {
13  [](T *ptr) -> T& { return *ptr; }(0);
14}
15
16template void call_with_zero<int>();
17
18template<typename T>
19T captures(T x, T y) {
20  auto lambda = [=, &y] () -> T {
21    T i = x;
22    return i + y;
23  };
24
25  return lambda();
26}
27
28struct X {
29  X(const X&);
30};
31
32X operator+(X, X);
33X operator-(X, X);
34
35template int captures(int, int);
36template X captures(X, X);
37
38template<typename T>
39int infer_result(T x, T y) {
40  auto lambda = [=](bool b) { return x + y; };
41  return lambda(true); // expected-error{{no viable conversion from 'X' to 'int'}}
42}
43
44template int infer_result(int, int);
45template int infer_result(X, X); // expected-note{{in instantiation of function template specialization 'infer_result<X>' requested here}}
46
47// Make sure that lambda's operator() can be used from templates.
48template<typename F>
49void accept_lambda(F f) {
50  f(1);
51}
52
53template<typename T>
54void pass_lambda(T x) {
55  accept_lambda([&x](T y) { return x + y; });
56}
57
58template void pass_lambda(int);
59
60namespace std {
61  class type_info;
62}
63
64namespace p2 {
65  struct P {
66    virtual ~P();
67  };
68
69  template<typename T>
70  struct Boom {
71    Boom(const Boom&) {
72      T* x = 1; // expected-error{{cannot initialize a variable of type 'int *' with an rvalue of type 'int'}} \
73      // expected-error{{cannot initialize a variable of type 'float *' with an rvalue of type 'int'}}
74    }
75    void tickle() const;
76  };
77
78  template<typename R, typename T>
79  void odr_used(R &r, Boom<T> boom) {
80    const std::type_info &ti
81      = typeid([=,&r] () -> R& { // expected-error{{lambda expression in an unevaluated operand}}
82          boom.tickle(); // expected-note{{in instantiation of member function}}
83          return r;
84        }());
85  }
86
87  template void odr_used(int&, Boom<int>); // expected-note{{in instantiation of function template specialization}}
88
89  template<typename R, typename T>
90  void odr_used2(R &r, Boom<T> boom) {
91    const std::type_info &ti
92      = typeid([=,&r] () -> R& {
93          boom.tickle(); // expected-note{{in instantiation of member function}}
94          return r;
95        }());
96  }
97
98  template void odr_used2(P&, Boom<float>);
99}
100
101namespace p5 {
102  struct NonConstCopy {
103    NonConstCopy(const NonConstCopy&) = delete;
104    NonConstCopy(NonConstCopy&);
105  };
106
107  template<typename T>
108  void double_capture(T &nc) {
109    [=] () mutable {
110      [=] () mutable {
111        T nc2(nc);
112      }();
113    }();
114  }
115
116  template void double_capture(NonConstCopy&);
117}
118
119namespace NonLocalLambdaInstantation {
120  template<typename T>
121  struct X {
122    static int value;
123  };
124
125  template<typename T>
126  int X<T>::value = []{ return T(); }(); // expected-error{{cannot initialize a variable of type 'int' with an rvalue of type 'int *'}}
127
128  template int X<int>::value;
129  template int X<float>::value;
130  template int X<int*>::value; // expected-note{{in instantiation of static data member }}
131
132  template<typename T>
133  void defaults(int x = []{ return T(); }()) { }; // expected-error{{cannot initialize a parameter of type 'int' with an rvalue of type 'int *'}} \
134     // expected-note{{passing argument to parameter 'x' here}}
135
136  void call_defaults() {
137    defaults<int>();
138    defaults<float>();
139    defaults<int*>(); // expected-note{{in instantiation of default function argument expression for 'defaults<int *>' required here}}
140  }
141
142  template<typename T>
143  struct X2 {
144    int x = []{ return T(); }(); // expected-error{{cannot initialize a member subobject of type 'int' with an rvalue of type 'int *'}}
145  };
146
147  X2<int> x2i;
148  X2<float> x2f;
149  X2<int*> x2ip; // expected-note{{in instantiation of template class 'NonLocalLambdaInstantation::X2<int *>' requested here}}
150}
151