xref: /llvm-project/clang/test/SemaCXX/cxx0x-initializer-stdinitializerlist.cpp (revision a7d5ec9a1fb253c7b2f1fb3dd6605707b30c57f0)
1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
2 
3 // This must obviously come before the definition of std::initializer_list.
4 void missing_initializerlist() {
5   auto l = {1, 2, 3, 4}; // expected-error {{std::initializer_list was not found}}
6 }
7 
8 namespace std {
9   typedef decltype(sizeof(int)) size_t;
10 
11   // libc++'s implementation
12   template <class _E>
13   class initializer_list
14   {
15     const _E* __begin_;
16     size_t    __size_;
17 
18     initializer_list(const _E* __b, size_t __s)
19       : __begin_(__b),
20         __size_(__s)
21     {}
22 
23   public:
24     typedef _E        value_type;
25     typedef const _E& reference;
26     typedef const _E& const_reference;
27     typedef size_t    size_type;
28 
29     typedef const _E* iterator;
30     typedef const _E* const_iterator;
31 
32     initializer_list() : __begin_(nullptr), __size_(0) {}
33 
34     size_t    size()  const {return __size_;}
35     const _E* begin() const {return __begin_;}
36     const _E* end()   const {return __begin_ + __size_;}
37   };
38 }
39 
40 template <typename T, typename U>
41 struct same_type { static const bool value = false; };
42 template <typename T>
43 struct same_type<T, T> { static const bool value = true; };
44 
45 struct one { char c[1]; };
46 struct two { char c[2]; };
47 
48 struct A {
49   int a, b;
50 };
51 
52 struct B {
53   B();
54   B(int, int);
55 };
56 
57 void simple_list() {
58   std::initializer_list<int> il = { 1, 2, 3 };
59   std::initializer_list<double> dl = { 1.0, 2.0, 3 };
60   std::initializer_list<A> al = { {1, 2}, {2, 3}, {3, 4} };
61   std::initializer_list<B> bl = { {1, 2}, {2, 3}, {} };
62 }
63 
64 void function_call() {
65   void f(std::initializer_list<int>);
66   f({1, 2, 3});
67 
68   void g(std::initializer_list<B>);
69   g({ {1, 2}, {2, 3}, {} });
70 }
71 
72 struct C {
73   C(int);
74 };
75 
76 struct D {
77   D();
78   operator int();
79   operator C();
80 };
81 
82 void overloaded_call() {
83     one overloaded(std::initializer_list<int>);
84     two overloaded(std::initializer_list<B>);
85 
86     static_assert(sizeof(overloaded({1, 2, 3})) == sizeof(one), "bad overload");
87     static_assert(sizeof(overloaded({ {1, 2}, {2, 3}, {} })) == sizeof(two), "bad overload");
88 
89     void ambiguous(std::initializer_list<A>); // expected-note {{candidate}}
90     void ambiguous(std::initializer_list<B>); // expected-note {{candidate}}
91     ambiguous({ {1, 2}, {2, 3}, {3, 4} }); // expected-error {{ambiguous}}
92 
93     one ov2(std::initializer_list<int>); // expected-note {{candidate}}
94     two ov2(std::initializer_list<C>); // expected-note {{candidate}}
95     // Worst sequence to int is identity, whereas to C it's user-defined.
96     static_assert(sizeof(ov2({1, 2, 3})) == sizeof(one), "bad overload");
97     // But here, user-defined is worst in both cases.
98     ov2({1, 2, D()}); // expected-error {{ambiguous}}
99 }
100 
101 template <typename T>
102 T deduce(std::initializer_list<T>); // expected-note {{conflicting types for parameter 'T' ('int' vs. 'double')}}
103 template <typename T>
104 T deduce_ref(const std::initializer_list<T>&); // expected-note {{conflicting types for parameter 'T' ('int' vs. 'double')}}
105 
106 template<typename T, typename U> struct pair { pair(...); };
107 template<typename T> void deduce_pairs(std::initializer_list<pair<T, typename T::type>>); // expected-note {{something}}
108 struct WithIntType { typedef int type; };
109 
110 template<typename ...T> void deduce_after_init_list_in_pack(void (*)(T...), T...); // expected-note {{<int, int> vs. <(no value), double>}}
111 
112 void argument_deduction() {
113   static_assert(same_type<decltype(deduce({1, 2, 3})), int>::value, "bad deduction");
114   static_assert(same_type<decltype(deduce({1.0, 2.0, 3.0})), double>::value, "bad deduction");
115 
116   deduce({1, 2.0}); // expected-error {{no matching function}}
117 
118   static_assert(same_type<decltype(deduce_ref({1, 2, 3})), int>::value, "bad deduction");
119   static_assert(same_type<decltype(deduce_ref({1.0, 2.0, 3.0})), double>::value, "bad deduction");
120 
121   deduce_ref({1, 2.0}); // expected-error {{no matching function}}
122 
123   pair<WithIntType, int> pi;
124   pair<WithIntType, float> pf;
125   deduce_pairs({pi, pi, pi}); // ok
126   deduce_pairs({pi, pf, pi}); // expected-error {{no matching function}}
127 
128   deduce_after_init_list_in_pack((void(*)(int,int))0, {}, 0);
129   deduce_after_init_list_in_pack((void(*)(int,int))0, {}, 0.0); // expected-error {{no matching function}}
130 }
131 
132 void auto_deduction() {
133   auto l = {1, 2, 3, 4};
134   auto l2 {1, 2, 3, 4}; // expected-error {{initializer for variable 'l2' with type 'auto' contains multiple expressions}}
135   auto l3 {1};
136   static_assert(same_type<decltype(l), std::initializer_list<int>>::value, "");
137   static_assert(same_type<decltype(l3), int>::value, "");
138   auto bl = {1, 2.0}; // expected-error {{cannot deduce}}
139 
140   for (int i : {1, 2, 3, 4}) {}
141 }
142 
143 void dangle() {
144   new auto{1, 2, 3}; // expected-error {{cannot use list-initialization}}
145   new std::initializer_list<int>{1, 2, 3}; // expected-warning {{at the end of the full-expression}}
146 }
147 
148 struct haslist1 {
149   std::initializer_list<int> il = {1, 2, 3}; // expected-warning{{at the end of the constructor}}
150   std::initializer_list<int> jl{1, 2, 3}; // expected-warning{{at the end of the constructor}}
151   haslist1();
152 };
153 
154 haslist1::haslist1()
155 : il{1, 2, 3} // expected-warning{{at the end of the constructor}}
156 {}
157 
158 namespace PR12119 {
159   // Deduction with nested initializer lists.
160   template<typename T> void f(std::initializer_list<T>);
161   template<typename T> void g(std::initializer_list<std::initializer_list<T>>);
162 
163   void foo() {
164     f({0, {1}}); // expected-warning{{braces around scalar initializer}}
165     g({{0, 1}, {2, 3}});
166     std::initializer_list<int> il = {1, 2};
167     g({il, {2, 3}});
168   }
169 }
170 
171 namespace Decay {
172   template<typename T>
173   void f(std::initializer_list<T>) {
174     T x = 1; // expected-error{{cannot initialize a variable of type 'const char *' with an rvalue of type 'int'}}
175   }
176 
177   void g() {
178     f({"A", "BB", "CCC"}); // expected-note{{in instantiation of function template specialization 'Decay::f<const char *>' requested here}}
179 
180     auto x = { "A", "BB", "CCC" };
181     std::initializer_list<const char *> *il = &x;
182 
183     for( auto s : {"A", "BB", "CCC", "DDD"}) { }
184   }
185 }
186 
187 namespace PR12436 {
188   struct X {
189     template<typename T>
190     X(std::initializer_list<int>, T);
191   };
192 
193   X x({}, 17);
194 }
195 
196 namespace rdar11948732 {
197   template<typename T> struct X {};
198 
199   struct XCtorInit {
200     XCtorInit(std::initializer_list<X<int>>);
201   };
202 
203   void f(X<int> &xi) {
204     XCtorInit xc = { xi, xi };
205   }
206 }
207 
208 namespace PR14272 {
209   auto x { { 0, 0 } }; // expected-error {{cannot deduce type for variable 'x' with type 'auto' from nested initializer list}}
210 }
211 
212 namespace initlist_of_array {
213   void f(std::initializer_list<int[2]>) {}
214   void f(std::initializer_list<int[2][2]>) = delete;
215   void h() {
216     f({{1,2},{3,4}});
217   }
218 }
219 
220 namespace init_list_deduction_failure {
221   void f();
222   void f(int);
223   template<typename T> void g(std::initializer_list<T>);
224   // expected-note@-1 {{candidate template ignored: couldn't resolve reference to overloaded function 'f'}}
225   void h() { g({f}); }
226   // expected-error@-1 {{no matching function for call to 'g'}}
227 }
228 
229 namespace deleted_copy {
230   struct X {
231     X(int i) {}
232     X(const X& x) = delete; // expected-note {{here}}
233     void operator=(const X& x) = delete;
234   };
235 
236   std::initializer_list<X> x{1}; // expected-error {{invokes deleted constructor}}
237 }
238 
239 namespace RefVersusInitList {
240   struct S {};
241   void f(const S &) = delete;
242   void f(std::initializer_list<S>);
243   void g(S s) { f({S()}); }
244 }
245 
246 namespace PR18013 {
247   int f();
248   std::initializer_list<long (*)()> x = {f}; // expected-error {{cannot initialize an array element of type 'long (*const)()' with an lvalue of type 'int ()': different return type ('long' vs 'int')}}
249 }
250 
251 namespace DR1070 {
252   struct S {
253     S(std::initializer_list<int>);
254   };
255   S s[3] = { {1, 2, 3}, {4, 5} }; // ok
256   S *p = new S[3] { {1, 2, 3}, {4, 5} }; // ok
257 }
258 
259 namespace ListInitInstantiate {
260   struct A {
261     A(std::initializer_list<A>);
262     A(std::initializer_list<int>);
263   };
264   struct B : A {
265     B(int);
266   };
267   template<typename T> struct X {
268     X();
269     A a;
270   };
271   template<typename T> X<T>::X() : a{B{0}, B{1}} {}
272 
273   X<int> x;
274 
275   int f(const A&);
276   template<typename T> void g() { int k = f({0}); }
277   template void g<int>();
278 }
279 
280 namespace TemporaryInitListSourceRange_PR22367 {
281   struct A {
282     constexpr A() {}
283     A(std::initializer_list<int>); // expected-note {{here}}
284   };
285   constexpr int f(A) { return 0; }
286   constexpr int k = f( // expected-error {{must be initialized by a constant expression}}
287       // The point of this test is to check that the caret points to
288       // 'std::initializer_list', not to '{0}'.
289       std::initializer_list // expected-note {{constructor}}
290       <int>
291       {0}
292       );
293 }
294 
295 namespace ParameterPackNestedInitializerLists_PR23904c3 {
296   template <typename ...T>
297   void f(std::initializer_list<std::initializer_list<T>> ...tt);
298 
299   void foo() { f({{0}}, {{'\0'}}); }
300 }
301 
302 namespace update_rbrace_loc_crash {
303   // We used to crash-on-invalid on this example when updating the right brace
304   // location.
305   template <typename T, T>
306   struct A {};
307   template <typename T, typename F, int... I>
308   std::initializer_list<T> ExplodeImpl(F p1, A<int, I...>) {
309     // expected-error@+1 {{reference to type 'const update_rbrace_loc_crash::Incomplete' could not bind to an rvalue of type 'void'}}
310     return {p1(I)...};
311   }
312   template <typename T, int N, typename F>
313   void Explode(F p1) {
314     // expected-note@+1 {{in instantiation of function template specialization}}
315     ExplodeImpl<T>(p1, A<int, N>());
316   }
317   class Incomplete;
318   struct ContainsIncomplete {
319     const Incomplete &obstacle;
320   };
321   void f() {
322     // expected-note@+1 {{in instantiation of function template specialization}}
323     Explode<ContainsIncomplete, 4>([](int) {});
324   }
325 }
326