1 // RUN: %clang_cc1 -verify -std=c++2b -Wall -Wshadow %s
2 
3 void f() {
4 
5     for (using foo = int;true;) {} //expected-warning {{unused type alias 'foo'}}
6 
7     switch(using foo = int; 0) { //expected-warning {{unused type alias 'foo'}}
8         case 0: break;
9     }
10 
11     if(using foo = int; false) {} // expected-warning {{unused type alias 'foo'}}
12 
13     int x; // expected-warning {{unused variable 'x'}}
14     if(using x = int; true) {}  // expected-warning {{unused type alias 'x'}}
15 
16     using y = int; // expected-warning {{unused type alias 'y'}} \
17                    // expected-note 2{{previous declaration is here}}
18 
19     if(using y = double; true) {}  // expected-warning {{unused type alias 'y'}} \
20                                    // expected-warning {{declaration shadows a type alias in function 'f'}}
21 
22     for(using y = double; true;) { // expected-warning {{declaration shadows a type alias in function 'f'}}
23         y foo = 0;
24         (void)foo;
25         constexpr y var = 0;
26         static_assert(var == 0);
27     }
28 }
29