1 // RUN: %check_clang_tidy %s performance-move-const-arg %t \
2 // RUN: -config='{CheckOptions: \
3 // RUN:  [{key: performance-move-const-arg.CheckTriviallyCopyableMove, value: 0}]}'
4 
5 namespace std {
6 
7 template <typename> struct remove_reference;
8 template <typename _Tp> struct remove_reference { typedef _Tp type; };
9 template <typename _Tp> struct remove_reference<_Tp &> { typedef _Tp type; };
10 template <typename _Tp> struct remove_reference<_Tp &&> { typedef _Tp type; };
11 
12 template <typename _Tp>
move(_Tp && __t)13 constexpr typename std::remove_reference<_Tp>::type &&move(_Tp &&__t) {
14   return static_cast<typename std::remove_reference<_Tp>::type &&>(__t);
15 }
16 
17 template <typename _Tp>
18 constexpr _Tp &&
forward(typename remove_reference<_Tp>::type & __t)19 forward(typename remove_reference<_Tp>::type &__t) noexcept {
20   return static_cast<_Tp &&>(__t);
21 }
22 
23 } // namespace std
24 
25 class NoMoveSemantics {
26  public:
27   NoMoveSemantics();
28   NoMoveSemantics(const NoMoveSemantics &);
29 
30   NoMoveSemantics &operator=(const NoMoveSemantics &);
31 };
32 
33 void callByConstRef(const NoMoveSemantics &);
34 void callByConstRef(int i, const NoMoveSemantics &);
35 
moveToConstReferencePositives()36 void moveToConstReferencePositives() {
37   NoMoveSemantics obj;
38 
39   // Basic case. It is here just to have a single "detected and fixed" case.
40   callByConstRef(std::move(obj));
41   // CHECK-MESSAGES: :[[@LINE-1]]:18:  warning: passing result of std::move() as a const reference argument; no move will actually happen [performance-move-const-arg]
42   // CHECK-FIXES: callByConstRef(obj);
43 }
44 
45 struct TriviallyCopyable {
46   int i;
47 };
48 
f(TriviallyCopyable)49 void f(TriviallyCopyable) {}
50 
g()51 void g() {
52   TriviallyCopyable obj;
53   f(std::move(obj));
54 }
55 
56 class MoveSemantics {
57  public:
58   MoveSemantics();
59   MoveSemantics(MoveSemantics &&);
60 
61   MoveSemantics &operator=(MoveSemantics &&);
62 };
63 
64 void fmovable(MoveSemantics);
65 
lambda1()66 void lambda1() {
67   auto f = [](MoveSemantics m) {
68     fmovable(std::move(m));
69   };
70   f(MoveSemantics());
71 }
72 
73 template<class T> struct function {};
74 
75 template<typename Result, typename... Args>
76 class function<Result(Args...)> {
77 public:
78   function() = default;
operator ()(Args...args) const79   void operator()(Args... args) const {
80     fmovable(std::forward<Args>(args)...);
81   }
82 };
83 
functionInvocation()84 void functionInvocation() {
85   function<void(MoveSemantics)> callback;
86   MoveSemantics m;
87   callback(std::move(m));
88 }
89 
lambda2()90 void lambda2() {
91   function<void(MoveSemantics)> callback;
92 
93   auto f = [callback = std::move(callback)](MoveSemantics m) mutable {
94     callback(std::move(m));
95   };
96   f(MoveSemantics());
97 }
98