1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <functional>
10 
11 // reference_wrapper
12 
13 // template <ObjectType T> reference_wrapper<T> ref(reference_wrapper<T>t);
14 
15 #include <functional>
16 #include <cassert>
17 
18 #include "counting_predicates.h"
19 
20 #include "test_macros.h"
21 
is5(int i)22 bool is5 ( int i ) { return i == 5; }
23 
24 template <typename T>
call_pred(T pred)25 bool call_pred ( T pred ) { return pred(5); }
26 
27 namespace adl {
28   struct A {};
ref(A)29   void ref(A) {}
30 }
31 
main(int,char **)32 int main(int, char**)
33 {
34     {
35     int i = 0;
36     std::reference_wrapper<int> r1 = std::ref(i);
37     std::reference_wrapper<int> r2 = std::ref(r1);
38     assert(&r2.get() == &i);
39     }
40     {
41     adl::A a;
42     std::reference_wrapper<adl::A> a1 = std::ref(a);
43     std::reference_wrapper<adl::A> a2 = std::ref(a1);
44     assert(&a2.get() == &a);
45     }
46 
47     {
48     unary_counting_predicate<bool(*)(int), int> cp(is5);
49     assert(!cp(6));
50     assert(cp.count() == 1);
51     assert(call_pred(cp));
52     assert(cp.count() == 1);
53     assert(call_pred(std::ref(cp)));
54     assert(cp.count() == 2);
55     }
56 
57   return 0;
58 }
59