p5-generic-lambda-1y.cpp revision 651f13cea278ec967336033dd032faef0e9fc2ec 
1// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++1y -DCXX1Y
2
3namespace test_factorial {
4
5auto Fact = [](auto Self, unsigned n) -> unsigned {
6    return !n ? 1 : Self(Self, n - 1) * n;
7};
8
9auto six = Fact(Fact, 3);
10
11}
12
13namespace overload_generic_lambda {
14  template <class F1, class F2> struct overload : F1, F2 {
15    using F1::operator();
16    using F2::operator();
17    overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
18  };
19
20  auto NumParams = [](auto Self, auto h, auto ... rest) -> unsigned {
21    return 1 + Self(Self, rest...);
22  };
23  auto Base = [](auto Self, auto h) -> unsigned {
24      return 1;
25  };
26  overload<decltype(Base), decltype(NumParams)> O(Base, NumParams);
27  int num_params =  O(O, 5, 3, "abc", 3.14, 'a');
28}
29
30
31namespace overload_generic_lambda_return_type_deduction {
32  template <class F1, class F2> struct overload : F1, F2 {
33    using F1::operator();
34    using F2::operator();
35    overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
36  };
37
38  auto NumParams = [](auto Self, auto h, auto ... rest) {
39    return 1 + Self(Self, rest...);
40  };
41  auto Base = [](auto Self, auto h) {
42      return 1;
43  };
44  overload<decltype(Base), decltype(NumParams)> O(Base, NumParams);
45  int num_params =  O(O, 5, 3, "abc", 3.14, 'a');
46}
47
48namespace test_standard_p5 {
49// FIXME: This test should eventually compile without an explicit trailing return type
50auto glambda = [](auto a, auto&& b) ->bool { return a < b; };
51bool b = glambda(3, 3.14); // OK
52
53}
54namespace test_deduction_failure {
55 int test() {
56   auto g = [](auto *a) { //expected-note{{candidate template ignored}}
57    return a;
58   };
59   struct X { };
60   X *x;
61   g(x);
62   g(3); //expected-error{{no matching function}}
63   return 0;
64 }
65
66}
67
68namespace test_instantiation_or_sfinae_failure {
69int test2() {
70  {
71    auto L = [](auto *a) {
72                return (*a)(a); }; //expected-error{{called object type 'double' is not a function}}
73    double d;
74    L(&d); //expected-note{{in instantiation of}}
75    auto M = [](auto b) { return b; };
76    L(&M); // ok
77  }
78  {
79    auto L = [](auto *a) ->decltype (a->foo()) { //expected-note2{{candidate template ignored:}}
80                return (*a)(a); };
81    double d;
82    L(&d); //expected-error{{no matching function for call}}
83    auto M = [](auto b) { return b; };
84    L(&M); //expected-error{{no matching function for call}}
85
86  }
87  return 0;
88}
89
90
91}
92
93namespace test_misc {
94auto GL = [](auto a, decltype(a) b) //expected-note{{candidate function}}
95                -> int { return a + b; };
96
97void test() {
98   struct X { };
99   GL(3, X{}); //expected-error{{no matching function}}
100}
101
102void test2() {
103  auto l = [](auto *a) -> int {
104              (*a)(a); return 0; }; //expected-error{{called object type 'double' is not a function}}
105  l(&l);
106  double d;
107  l(&d); //expected-note{{in instantiation of}}
108}
109
110}
111
112namespace nested_lambdas {
113  int test() {
114    auto L = [](auto a) {
115                 return [=](auto b) {
116                           return a + b;
117                        };
118              };
119  }
120  auto get_lambda() {
121    return [](auto a) {
122      return a;
123    };
124  };
125
126  int test2() {
127    auto L = get_lambda();
128    L(3);
129  }
130}
131
132