1 // RUN: %clang_cc1 -std=c++1z -verify %s -Wno-vexing-parse
2 
3 int g, h;
4 typedef int T;
f()5 int f() {
6   // init-statement declarations
7   if (T n = 0; n != 0) {}
8   if (T f(); f()) {}
9   if (T(f()); f()) {}
10   if (T(f()), g, h; f()) {}
11   if (T f(); f()) {}
12   if (T f(), g, h; f()) {}
13   if (T(n) = 0; n) {}
14 
15   // init-statement expressions
16   if (T{f()}; f()) {} // expected-warning {{expression result unused}}
17   if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
18   if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
19 
20   // condition declarations
21   if (T(n){g}) {}
22   if (T f()) {} // expected-error {{function type}}
23   if (T f(), g, h) {} // expected-error {{function type}}
24   if (T(n) = 0) {}
25 
26   // condition expressions
27   if (T(f())) {}
28   if (T{f()}) {}
29   if (T(f()), g, h) {} // expected-warning 2{{unused}}
30   if (T{f()}, g, h) {} // expected-warning 2{{unused}}
31 
32   // none of the above, disambiguated as expression (can't be a declaration)
33   if (T(n)(g)) {} // expected-error {{undeclared identifier 'n'}}
34   if (T(n)(int())) {} // expected-error {{undeclared identifier 'n'}}
35 
36   // Likewise for 'switch'
37   switch (int n; n) {}
38   switch (g; int g = 5) {} // expected-warning {{expression result unused}}
39 
40   if (int a, b; int c = a) { // expected-note 6{{previous}}
41     int a; // expected-error {{redefinition}}
42     int b; // expected-error {{redefinition}}
43     int c; // expected-error {{redefinition}}
44   } else {
45     int a; // expected-error {{redefinition}}
46     int b; // expected-error {{redefinition}}
47     int c; // expected-error {{redefinition}}
48   }
49 
50   return 0;
51 }
52