xref: /llvm-project/clang/test/SemaCXX/cxx1z-copy-omission.cpp (revision d4a2c7f95297d1865a457955dcf7b679dabb5e0e)
1 // RUN: %clang_cc1 -std=c++1z -verify -Wno-unused %s
2 // RUN: %clang_cc1 -std=c++1z -verify -Wno-unused %s -fexperimental-new-constant-interpreter
3 
4 struct Noncopyable {
5   Noncopyable();
6   Noncopyable(const Noncopyable &) = delete; // expected-note 1+{{deleted}} expected-note 1+ {{not viable}}
7   virtual ~Noncopyable();
8 };
9 struct Derived : Noncopyable {};
10 struct NoncopyableAggr { // expected-note 3{{candidate}}
11   Noncopyable nc;
12 };
13 struct Indestructible {
14   Indestructible();
15   ~Indestructible() = delete; // expected-note 1+{{deleted}}
16 };
17 struct Incomplete; // expected-note 1+{{declar}}
18 
make(int kind=0)19 Noncopyable make(int kind = 0) {
20   switch (kind) {
21   case 0: return {};
22   case 1: return Noncopyable();
23   case 2: return Noncopyable{};
24   case 3: return make();
25   }
26   __builtin_unreachable();
27 }
28 
29 Indestructible make_indestructible();
30 Incomplete make_incomplete(); // expected-note 1+{{here}}
31 
take(Noncopyable nc)32 void take(Noncopyable nc) {}
33 
nrvo()34 Noncopyable nrvo() {
35   Noncopyable nrvo;
36   return nrvo; // expected-error {{deleted constructor}}
37 }
38 
39 Noncopyable nc1 = make();
40 Noncopyable nc2 = Noncopyable();
41 Noncopyable nc3 = Derived(); // expected-error {{deleted constructor}}
42 Noncopyable nc4((Noncopyable()));
43 Noncopyable nc5 = {Noncopyable()};
44 Noncopyable nc6{Noncopyable()};
45 
46 NoncopyableAggr nca1 = NoncopyableAggr{};
47 NoncopyableAggr nca2 = NoncopyableAggr{{}};
48 NoncopyableAggr nca3 = NoncopyableAggr{NoncopyableAggr{Noncopyable()}};
49 
50 template<typename T> struct Convert { operator T(); }; // expected-note 1+{{candidate}}
51 Noncopyable conv1 = Convert<Noncopyable>();
52 Noncopyable conv2((Convert<Noncopyable>()));
53 Noncopyable conv3 = {Convert<Noncopyable>()};
54 Noncopyable conv4{Convert<Noncopyable>()};
55 
56 Noncopyable ref_conv1 = Convert<Noncopyable&>(); // expected-error {{deleted constructor}}
57 Noncopyable ref_conv2((Convert<Noncopyable&>())); // expected-error {{deleted constructor}}
58 Noncopyable ref_conv3 = {Convert<Noncopyable&>()}; // expected-error {{deleted constructor}}
59 Noncopyable ref_conv4{Convert<Noncopyable&>()}; // expected-error {{deleted constructor}}
60 
61 Noncopyable derived_conv1 = Convert<Derived>(); // expected-error {{deleted constructor}}
62 Noncopyable derived_conv2((Convert<Derived>())); // expected-error {{deleted constructor}}
63 Noncopyable derived_conv3 = {Convert<Derived>()}; // expected-error {{deleted constructor}}
64 Noncopyable derived_conv4{Convert<Derived>()}; // expected-error {{deleted constructor}}
65 
66 NoncopyableAggr nc_aggr1 = Convert<NoncopyableAggr>();
67 NoncopyableAggr nc_aggr2((Convert<NoncopyableAggr>()));
68 NoncopyableAggr nc_aggr3 = {Convert<NoncopyableAggr>()}; // expected-error {{no viable conversion}}
69 NoncopyableAggr nc_aggr4{Convert<NoncopyableAggr>()}; // expected-error {{no viable conversion}}
70 NoncopyableAggr nc_aggr5 = Convert<Noncopyable>(); // expected-error {{no viable}}
71 NoncopyableAggr nc_aggr6((Convert<Noncopyable>())); // expected-error {{no matching constructor}}
72 NoncopyableAggr nc_aggr7 = {Convert<Noncopyable>()};
73 NoncopyableAggr nc_aggr8{Convert<Noncopyable>()};
74 
test_expressions(bool b)75 void test_expressions(bool b) {
76   auto lambda = [a = make()] {};
77 
78   take({});
79   take(Noncopyable());
80   take(Noncopyable{});
81   take(make());
82 
83   Noncopyable &&dc1 = dynamic_cast<Noncopyable&&>(Noncopyable());
84   Noncopyable &&dc2 = dynamic_cast<Noncopyable&&>(nc1);
85   Noncopyable &&dc3 = dynamic_cast<Noncopyable&&>(Derived());
86 
87   Noncopyable sc1 = static_cast<Noncopyable>(Noncopyable());
88   Noncopyable sc2 = static_cast<Noncopyable>(nc1); // expected-error {{deleted}}
89   Noncopyable sc3 = static_cast<Noncopyable&&>(Noncopyable()); // expected-error {{deleted}}
90   Noncopyable sc4 = static_cast<Noncopyable>(static_cast<Noncopyable&&>(Noncopyable())); // expected-error {{deleted}}
91 
92   Noncopyable cc1 = (Noncopyable)Noncopyable();
93   Noncopyable cc2 = (Noncopyable)Derived(); // expected-error {{deleted}}
94 
95   Noncopyable fc1 = Noncopyable(Noncopyable());
96   Noncopyable fc2 = Noncopyable(Derived()); // expected-error {{deleted}}
97 
98   // We must check for a complete type for every materialized temporary. (Note
99   // that in the special case of the top level of a decltype, no temporary is
100   // materialized.)
101   make_incomplete(); // expected-error {{incomplete}}
102   make_incomplete().a; // expected-error {{incomplete}}
103   make_incomplete().*(int Incomplete::*)nullptr; // expected-error {{incomplete}}
104   dynamic_cast<Incomplete&&>(make_incomplete()); // expected-error {{incomplete}}
105   const_cast<Incomplete&&>(make_incomplete()); // expected-error {{incomplete}}
106 
107   sizeof(Indestructible{}); // expected-error {{deleted}}
108   sizeof(make_indestructible()); // expected-error {{deleted}}
109   sizeof(make_incomplete()); // expected-error {{incomplete}}
110   typeid(Indestructible{}); // expected-error {{deleted}} expected-error {{you need to include <typeinfo>}}
111   typeid(make_indestructible()); // expected-error {{deleted}} \
112                                  // expected-error {{need to include <typeinfo>}}
113   typeid(make_incomplete()); // expected-error {{incomplete}} \
114                              // expected-error {{need to include <typeinfo>}}
115 
116   // FIXME: The first two cases here are now also valid in C++17 onwards.
117   using I = decltype(Indestructible()); // expected-error {{deleted}}
118   using I = decltype(Indestructible{}); // expected-error {{deleted}}
119   using I = decltype(make_indestructible());
120   using J = decltype(make_incomplete());
121 
122   Noncopyable cond1 = b ? Noncopyable() : make();
123   Noncopyable cond2 = b ? Noncopyable() : Derived(); // expected-error {{incompatible}}
124   Noncopyable cond3 = b ? Derived() : Noncopyable(); // expected-error {{incompatible}}
125   Noncopyable cond4 = b ? Noncopyable() : nc1; // expected-error {{deleted}}
126   Noncopyable cond5 = b ? nc1 : Noncopyable(); // expected-error {{deleted}}
127   // Could convert both to an xvalue of type Noncopyable here, but we're not
128   // permitted to consider that.
129   Noncopyable &&cond6 = b ? Noncopyable() : Derived(); // expected-error {{incompatible}}
130   Noncopyable &&cond7 = b ? Derived() : Noncopyable(); // expected-error {{incompatible}}
131   // Could convert both to a const lvalue of type Noncopyable here, but we're
132   // not permitted to consider that, either.
133   const Noncopyable cnc;
134   const Noncopyable &cond8 = b ? cnc : Derived(); // expected-error {{incompatible}}
135   const Noncopyable &cond9 = b ? Derived() : cnc; // expected-error {{incompatible}}
136 
137   extern const volatile Noncopyable make_cv();
138   Noncopyable cv_difference1 = make_cv();
139   const volatile Noncopyable cv_difference2 = make();
140 }
141 
142 template<typename T> struct ConversionFunction { operator T(); };
143 Noncopyable cf1 = ConversionFunction<Noncopyable>();
144 Noncopyable cf2 = ConversionFunction<Noncopyable&&>(); // expected-error {{deleted}}
145 Noncopyable cf3 = ConversionFunction<const volatile Noncopyable>();
146 const volatile Noncopyable cf4 = ConversionFunction<Noncopyable>();
147 Noncopyable cf5 = ConversionFunction<Derived>(); // expected-error {{deleted}}
148 
149 struct AsMember {
150   Noncopyable member;
AsMemberAsMember151   AsMember() : member(make()) {}
152 };
153 // FIXME: DR (no number yet): we still get a copy for base or delegating construction.
154 struct AsBase : Noncopyable {
AsBaseAsBase155   AsBase() : Noncopyable(make()) {} // expected-error {{deleted}}
156 };
157 struct AsDelegating final {
158   AsDelegating(const AsDelegating &) = delete; // expected-note {{deleted}}
159   static AsDelegating make(int);
160 
161   // The base constructor version of this is problematic; the complete object
162   // version would be OK. Perhaps we could allow copy omission here for final
163   // classes?
AsDelegatingAsDelegating164   AsDelegating(int n) : AsDelegating(make(n)) {} // expected-error {{deleted}}
165 };
166 
167 namespace CtorTemplateBeatsNonTemplateConversionFn {
168   struct Foo { template <typename Derived> Foo(const Derived &); };
169   template <typename Derived> struct Base { operator Foo() const = delete; }; // expected-note {{deleted}}
170   struct Derived : Base<Derived> {};
171 
f(Derived d)172   Foo f(Derived d) { return d; } // expected-error {{invokes a deleted function}}
g(Derived d)173   Foo g(Derived d) { return Foo(d); } // ok, calls constructor
174 }
175 
176 // Make sure we don't consider conversion functions for guaranteed copy elision
177 namespace GH39319 {
178 struct A {
179   A();
180   A(const A&) = delete; // expected-note {{'A' has been explicitly marked deleted here}}
181 };
182 struct B {
183   operator A();
184 } C;
A()185 A::A() : A(C) {} // expected-error {{call to deleted constructor of}}
186 
187 struct A2 {
188   struct B2 {
189     operator A2();
190   };
A2GH39319::A2191   A2() : A2(B2()) {}  // expected-error {{call to deleted constructor of}}
192   A2(const A2&) = delete; // expected-note {{'A2' has been explicitly marked deleted here}}
193 };
194 
195 template<typename A3>
196 class B3 : A3 {
197   template<bool = C3<B3>()> // expected-warning 2{{use of function template name with no prior declaration in function call with explicit}}
198   B3();
199 }; B3(); // expected-error {{deduction guide declaration without trailing return type}} \
200          // expected-note {{while building implicit deduction guide first needed here}}
201 }
202