1 // RUN: %clang_cc1 -std=c++1z %s -verify
2
3 namespace std {
4 template<typename> struct tuple_size;
5 template<int, typename> struct tuple_element;
6 }
7
8 struct Get {
getGet9 template<int> int get() { return 0; }
operator boolGet10 operator bool() { return true; }
11 };
12
13 namespace std {
14 template<> struct tuple_size<Get> { static constexpr int value = 1; };
15 template<> struct tuple_element<0, Get> { using type = int; };
16 }
17
18 struct Na {
19 bool flag;
20 float data;
21 };
22
23 struct Rst {
24 bool flag;
25 float data;
operator boolRst26 explicit operator bool() const {
27 return flag;
28 }
29 };
30
31 Rst f();
32 Na g();
33
34 namespace CondInIf {
h()35 int h() {
36 if (auto [ok, d] = f()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
37 ;
38 if (auto [ok, d] = g()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}} expected-error {{value of type 'Na' is not contextually convertible to 'bool'}}
39 ;
40 if (auto [value] = Get()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
41 return value;
42 }
43 } // namespace CondInIf
44
45 namespace CondInWhile {
h()46 int h() {
47 while (auto [ok, d] = f()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
48 ;
49 while (auto [ok, d] = g()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}} expected-error {{value of type 'Na' is not contextually convertible to 'bool'}}
50 ;
51 while (auto [value] = Get()) // expected-warning{{ISO C++17 does not permit structured binding declaration in a condition}}
52 return value;
53 }
54 } // namespace CondInWhile
55
56 namespace CondInFor {
h()57 int h() {
58 for (; auto [ok, d] = f();) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
59 ;
60 for (; auto [ok, d] = g();) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}} expected-error {{value of type 'Na' is not contextually convertible to 'bool'}}
61 ;
62 for (; auto [value] = Get();) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
63 return value;
64 }
65 } // namespace CondInFor
66
67 struct IntegerLike {
68 bool flag;
69 float data;
operator intIntegerLike70 operator int() const {
71 return int(data);
72 }
73 };
74
75 namespace CondInSwitch {
h(IntegerLike x)76 int h(IntegerLike x) {
77 switch (auto [ok, d] = x) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
78 ;
79 switch (auto [ok, d] = g()) // expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}} expected-error {{statement requires expression of integer type ('Na' invalid)}}
80 ;
81 switch (auto [value] = Get()) {// expected-warning {{ISO C++17 does not permit structured binding declaration in a condition}}
82 // expected-warning@-1{{switch condition has boolean value}}
83 case 1:
84 return value;
85 }
86 }
87 } // namespace CondInSwitch
88