1// RUN: %clang_cc1 -fsyntax-only -std=c++1y %s -verify
2
3int a;
4int &b = [] (int &r) -> decltype(auto) { return r; } (a);
5int &c = [] (int &r) -> decltype(auto) { return (r); } (a);
6int &d = [] (int &r) -> auto & { return r; } (a);
7int &e = [] (int &r) -> auto { return r; } (a); // expected-error {{cannot bind to a temporary}}
8int &f = [] (int r) -> decltype(auto) { return r; } (a); // expected-error {{cannot bind to a temporary}}
9int &g = [] (int r) -> decltype(auto) { return (r); } (a); // expected-warning {{reference to stack}}
10
11
12int test_explicit_auto_return()
13{
14    struct X {};
15    auto L = [](auto F, auto a) { return F(a); };
16    auto M = [](auto a) -> auto { return a; }; // OK
17    auto MRef = [](auto b) -> auto& { return b; }; //expected-warning{{reference to stack}}
18    auto MPtr = [](auto c) -> auto* { return &c; }; //expected-warning{{address of stack}}
19    auto MDeclType = [](auto&& d) -> decltype(auto) { return static_cast<decltype(d)>(d); }; //OK
20    M(3);
21
22    auto &&x = MDeclType(X{});
23    auto &&x1 = M(X{});
24    auto &&x2 = MRef(X{});//expected-note{{in instantiation of}}
25    auto &&x3 = MPtr(X{}); //expected-note{{in instantiation of}}
26    return 0;
27}
28
29int test_implicit_auto_return()
30{
31  {
32    auto M = [](auto a) { return a; };
33    struct X {};
34    X x = M(X{});
35
36  }
37}
38
39int test_multiple_returns()  {
40    auto M = [](auto a) {
41      bool k;
42      if (k)
43        return a;
44      else
45        return 5; //expected-error{{deduced as 'int' here}}
46    };
47    M(3); // OK
48    M('a'); //expected-note{{in instantiation of}}
49  return 0;
50}
51int test_no_parameter_list()
52{
53  static int si = 0;
54    auto M = [] { return 5; }; // OK
55    auto M2 = [] -> auto&& { return si; }; // expected-error{{lambda requires '()'}}
56    M();
57}
58
59int test_conditional_in_return() {
60  auto Fac = [](auto f, auto n) {
61    return n <= 0 ? n : f(f, n - 1) * n;
62  };
63  // FIXME: this test causes a recursive limit - need to error more gracefully.
64  //Fac(Fac, 3);
65
66}