1 // RUN: %clang_cc1 -std=c++98 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
2 // RUN: %clang_cc1 -std=c++11 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
3 // RUN: %clang_cc1 -std=c++14 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
4 // RUN: %clang_cc1 -std=c++17 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
5 
6 __extension__ typedef __SIZE_TYPE__ size_t;
7 
8 namespace std {
9   template<typename T> struct initializer_list {
10     const T *ptr;
11     size_t n;
12     initializer_list(const T*, size_t);
13   };
14 }
15 
16 namespace dr1310 { // dr1310: 5
17   struct S {} * sp = new S::S; // expected-error {{qualified reference to 'S' is a constructor name}}
f()18   void f() {
19     S::S(a); // expected-error {{qualified reference to 'S' is a constructor name}}
20   }
21   struct T { int n; typedef int U; typedef T V; };
22   int k = T().T::T::n;
23   T::V v;
24 
25   struct U { int U; };
26   int u = U().U::U;
27   struct U::U w;
28 
29   struct V : T::T {
30     // FIXME: This is technically ill-formed, but we consider that to be a defect.
Vdr1310::V31     V() : T::T() {}
32   };
33   template<typename T> struct VT : T::T {
VTdr1310::VT34     VT() : T::T() {}
35   };
36   template struct VT<T>;
37 
38   template<template<typename> class> class TT {};
39   template<typename> class TTy {};
40 
41   template<typename T> struct WBase {};
42   template<typename T> struct W : WBase<T> { typedef int X; int n; };
43 
w_test()44   void w_test() {
45     W<int>::W w1a; // expected-error {{qualified reference to 'W' is a constructor name}}
46     W<int>::W::X w1ax;
47     W<int>::W<int> w1b; // expected-error {{qualified reference to 'W' is a constructor name}}
48     W<int>::W<int>::X w1bx;
49     typename W<int>::W w2a; // expected-error {{qualified reference to 'W' is a constructor name}} expected-error 0-1{{outside of a template}}
50     typename W<int>::W::X w2ax; // expected-error 0-1{{outside of a template}}
51     typename W<int>::W<int> w2b; // expected-error {{qualified reference to 'W' is a constructor name}} expected-error 0-1{{outside of a template}}
52     typename W<int>::W<int>::X w2bx; // expected-error 0-1{{outside of a template}}
53     W<int>::template W<int> w3; // expected-error {{qualified reference to 'W' is a constructor name}} expected-error 0-1{{outside of a template}}
54     W<int>::template W<int>::X w3x; // expected-error 0-1{{outside of a template}}
55     typename W<int>::template W<int> w4; // expected-error {{qualified reference to 'W' is a constructor name}} expected-error 0-2{{outside of a template}}
56     typename W<int>::template W<int>::X w4x; // expected-error 0-2{{outside of a template}}
57 
58     TT<W<int>::W> tt1; // expected-error {{qualified reference to 'W' is a constructor name}}
59     TTy<W<int>::W> tt1a; // expected-error {{qualified reference to 'W' is a constructor name}}
60     TT<W<int>::template W> tt2; // expected-error {{qualified reference to 'W' is a constructor name}} expected-error 0-1{{outside of a template}}
61     TT<W<int>::WBase> tt3;
62     TTy<W<int>::WBase> tt3a;
63     TT<W<int>::template WBase> tt4; // expected-error 0-1{{outside of a template}}
64 
65     W<int> w;
66     (void)w.W::W::n;
67     (void)w.W<int>::W::n;
68     (void)w.W<int>::W<int>::n;
69     (void)w.W<int>::template W<int>::n; // expected-error 0-1{{outside of a template}}
70   }
71 
72   template<typename W>
wt_test()73   void wt_test() {
74     typename W::W w2a; // expected-error {{qualified reference to 'W' is a constructor name}}
75     typename W::template W<int> w4; // expected-error {{qualified reference to 'W' is a constructor name}}
76     TTy<typename W::W> tt2; // expected-error {{qualified reference to 'W' is a constructor name}}
77     TT<W::template W> tt3; // expected-error {{qualified reference to 'W' is a constructor name}}
78   }
79   template<typename W>
wt_test_good()80   void wt_test_good() {
81     typename W::W::X w2ax;
82     typename W::template W<int>::X w4x;
83     TTy<typename W::WBase> tt4;
84     TT<W::template WBase> tt5;
85 
86     W w;
87     (void)w.W::W::n;
88     (void)w.W::template W<int>::n;
89     (void)w.template W<int>::W::n;
90     (void)w.template W<int>::template W<int>::n;
91   }
92   template void wt_test<W<int> >(); // expected-note {{instantiation of}}
93   template void wt_test_good<W<int> >();
94 }
95 
96 namespace dr1315 { // dr1315: partial
97   template <int I, int J> struct A {};
98   template <int I> // expected-note {{non-deducible template parameter 'I'}}
99     struct A<I + 5, I * 2> {}; // expected-error {{contains a template parameter that cannot be deduced}}
100   template <int I> struct A<I, I> {};
101 
102   template <int I, int J, int K> struct B;
103   template <int I, int K> struct B<I, I * 2, K> {}; // expected-note {{matches}}
104   B<1, 2, 3> b1;
105 
106   // Multiple declarations with the same dependent expression are equivalent
107   // for partial ordering purposes.
108   template <int I> struct B<I, I * 2, 2> { typedef int type; };
109   B<1, 2, 2>::type b2;
110 
111   // Multiple declarations with differing dependent expressions are unordered.
112   template <int I, int K> struct B<I, I + 1, K> {}; // expected-note {{matches}}
113   B<1, 2, 4> b3; // expected-error {{ambiguous}}
114 
115   // FIXME: Under dr1315, this is perhaps valid, but that is not clear: this
116   // fails the "more specialized than the primary template" test because the
117   // dependent type of T::value is not the same as 'int'.
118   // A core issue will be opened to decide what is supposed to happen here.
119   template <typename T, int I> struct C;
120   template <typename T> struct C<T, T::value>;
121   // expected-error@-1 {{type of specialized non-type template argument depends on a template parameter of the partial specialization}}
122 }
123 
124 namespace dr1330 { // dr1330: 4 c++11
125   // exception-specifications are parsed in a context where the class is complete.
126   struct A {
fdr1330::A127     void f() throw(T) {} // expected-error 0-1{{C++17}} expected-note 0-1{{noexcept}}
128     struct T {};
129 
130 #if __cplusplus >= 201103L
gdr1330::A131     void g() noexcept(&a == b) {}
132     static int a;
133     static constexpr int *b = &a;
134 #endif
135   };
136 
137   void (A::*af1)() throw(A::T) = &A::f; // expected-error 0-1{{C++17}} expected-note 0-1{{noexcept}}
138   void (A::*af2)() throw() = &A::f; // expected-error-re {{{{not superset|different exception spec}}}}
139 
140 #if __cplusplus >= 201103L
141   static_assert(noexcept(A().g()), "");
142 #endif
143 
144   // Likewise, they're instantiated separately from an enclosing class template.
145   template<typename U>
146   struct B {
fdr1330::B147     void f() throw(T, typename U::type) {} // expected-error 0-1{{C++17}} expected-note 0-1{{noexcept}}
148     struct T {};
149 
150 #if __cplusplus >= 201103L
gdr1330::B151     void g() noexcept(&a == b && U::value) {}
152     static int a;
153     static constexpr int *b = &a;
154 #endif
155   };
156 
157   B<int> bi; // ok
158 
159   struct P {
160     typedef int type;
161     static const int value = true;
162   };
163 
164   void (B<P>::*bpf1)() throw(B<P>::T, int) = &B<P>::f; // expected-error 0-1{{C++17}} expected-note 0-1{{noexcept}}
165 #if __cplusplus < 201103L
166   // expected-error@-2 {{not superset}}
167   // FIXME: We only delay instantiation in C++11 onwards. In C++98, something
168   // weird happens: instantiation of B<P> fails because it references T before
169   // it's instantiated, but the diagnostic is suppressed in
170   // Sema::FindInstantiatedDecl because we've already hit an error. This is
171   // obviously a bad way to react to this situation; we should still producing
172   // the "T has not yet been instantiated" error here, rather than giving
173   // confusing errors later on.
174 #endif
175   void (B<P>::*bpf2)() throw(int) = &B<P>::f; // expected-error 0-1{{C++17}} expected-note 0-1{{noexcept}}
176 #if __cplusplus <= 201402L
177   // expected-error@-2 {{not superset}}
178 #else
179   // expected-warning@-4 {{not superset}}
180 #endif
181   void (B<P>::*bpf3)() = &B<P>::f;
182   void (B<P>::*bpf4)() throw() = &B<P>::f;
183 #if __cplusplus <= 201402L
184   // expected-error@-2 {{not superset}}
185 #else
186   // expected-error@-4 {{different exception specifications}}
187 #endif
188 
189 #if __cplusplus >= 201103L
190   static_assert(noexcept(B<P>().g()), "");
191   struct Q { static const int value = false; };
192   static_assert(!noexcept(B<Q>().g()), "");
193 #endif
194 
f()195   template<typename T> int f() throw(typename T::error) { return 0; } // expected-error 1-4{{prior to '::'}} expected-note 0-1{{prior to '::'}} expected-note 0-1{{requested here}}
196 #if __cplusplus > 201402L
197     // expected-error@-2 0-1{{C++17}} expected-note@-2 0-1{{noexcept}}
198 #endif
199   // An exception-specification is needed even if the function is only used in
200   // an unevaluated operand.
201   int f1 = sizeof(f<int>()); // expected-note {{instantiation of}}
202 #if __cplusplus >= 201103L
203   decltype(f<char>()) f2; // expected-note {{instantiation of}}
204   bool f3 = noexcept(f<float>()); // expected-note {{instantiation of}}
205 #endif
206   // In C++17 onwards, substituting explicit template arguments into the
207   // function type substitutes into the exception specification (because it's
208   // part of the type). In earlier languages, we don't notice there's a problem
209   // until we've already started to instantiate.
210   template int f<short>();
211 #if __cplusplus >= 201703L
212   // expected-error@-2 {{does not refer to a function template}}
213 #else
214   // expected-note@-4 {{instantiation of}}
215 #endif
216 
217   template<typename T> struct C {
218     C() throw(typename T::type); // expected-error 1-2{{prior to '::'}}
219 #if __cplusplus > 201402L
220     // expected-error@-2 0-1{{C++17}} expected-note@-2 0-1{{noexcept}}
221 #endif
222   };
223   struct D : C<void> {}; // ok
224 #if __cplusplus < 201103L
225   // expected-note@-2 {{instantiation of}}
226 #endif
f(D & d)227   void f(D &d) { d = d; } // ok
228 
229   struct E : C<int> {}; // expected-note {{in instantiation of}}
230 #if __cplusplus >= 201103L
231   E e; // expected-note {{needed here}}
232 #endif
233 }
234 
235 namespace dr1346 { // dr1346: 3.5
236   auto a(1); // expected-error 0-1{{extension}}
237   auto b(1, 2); // expected-error {{multiple expressions}} expected-error 0-1{{extension}}
238 #if __cplusplus >= 201103L
239   auto c({}); // expected-error {{parenthesized initializer list}}
240   auto d({1}); // expected-error {{parenthesized initializer list}}
241   auto e({1, 2}); // expected-error {{parenthesized initializer list}}
242 #endif
f(Ts...ts)243   template<typename...Ts> void f(Ts ...ts) { // expected-error 0-1{{extension}}
244     auto x(ts...); // expected-error {{empty}} expected-error 0-1{{extension}}
245   }
246   template void f(); // expected-note {{instantiation}}
247 
248 #if __cplusplus >= 201103L
init_capture()249   void init_capture() {
250     [a(1)] {} (); // expected-error 0-1{{extension}}
251     [b(1, 2)] {} (); // expected-error {{multiple expressions}} expected-error 0-1{{extension}}
252 #if __cplusplus >= 201103L
253     [c({})] {} (); // expected-error {{parenthesized initializer list}} expected-error 0-1{{extension}}
254     [d({1})] {} (); // expected-error {{parenthesized initializer list}} expected-error 0-1{{extension}}
255     [e({1, 2})] {} (); // expected-error {{parenthesized initializer list}} expected-error 0-1{{extension}}
256 #endif
257   }
258 #endif
259 }
260 
261 namespace dr1347 { // dr1347: yes
262   auto x = 5, *y = &x; // expected-error 0-1{{extension}}
263   auto z = y, *q = y; // expected-error {{'auto' deduced as 'int *' in declaration of 'z' and deduced as 'int' in declaration of 'q'}} expected-error 0-1{{extension}}
264 #if __cplusplus >= 201103L
265   auto a = 5, b = {1, 2}; // expected-error {{'auto' deduced as 'int' in declaration of 'a' and deduced as 'std::initializer_list<int>' in declaration of 'b'}}
266   auto (*fp)(int) -> int, i = 0; // expected-error {{declaration with trailing return type must be the only declaration in its group}}
267 #endif
268 }
269 
270 namespace dr1358 { // dr1358: yes
271 #if __cplusplus >= 201103L
operator intdr1358::Lit272   struct Lit { constexpr operator int() const { return 0; } };
273   struct NonLit { NonLit(); operator int(); }; // expected-note 2{{no constexpr constructors}}
274   struct NonConstexprConv { constexpr operator int() const; };
275   struct Virt { virtual int f(int) const; };
276 
277   template<typename T, typename U, typename V> struct A : V {
278     int member;
Adr1358::A279     constexpr A(U u) : member(u) {}
fdr1358::A280     constexpr T f(U u) const { return T(); }
281   };
282 
283   constexpr A<Lit, Lit, Lit> ce = Lit();
284   constexpr int k = ce.f(Lit{});
285 
286   // Can have a non-literal return type and parameter type.
287   // Constexpr function can be implicitly virtual.
288   A<NonLit, NonLit, Virt> a = NonLit();
g()289   void g() { a.f(NonLit()); }
290 
291   // Constructor is still constexpr, so this is a literal type.
292   static_assert(__is_literal_type(decltype(a)), "");
293 
294   // Constructor can call non-constexpr functions.
295   A<Lit, NonConstexprConv, Lit> b = NonConstexprConv();
296 
297   // But the corresponding non-template cases are rejected.
298   struct B : Virt {
299     int member;
Bdr1358::B300     constexpr B(NonLit u) : member(u) {} // expected-error {{not a literal type}}
fdr1358::B301     constexpr NonLit f(NonLit u) const { return NonLit(); } // expected-error {{not a literal type}}
302   };
303 #endif
304 }
305 
306 namespace dr1359 { // dr1359: 3.5
307 #if __cplusplus >= 201103L
308   union A { constexpr A() = default; };
309   union B { constexpr B() = default; int a; }; // expected-error {{not constexpr}} expected-note 2{{candidate}}
310   union C { constexpr C() = default; int a, b; }; // expected-error {{not constexpr}} expected-note 2{{candidate}}
311   struct X { constexpr X() = default; union {}; }; // expected-error {{does not declare anything}}
312   struct Y { constexpr Y() = default; union { int a; }; }; // expected-error {{not constexpr}} expected-note 2{{candidate}}
313 
314   constexpr A a = A();
315   constexpr B b = B(); // expected-error {{no matching}}
316   constexpr C c = C(); // expected-error {{no matching}}
317   constexpr X x = X();
318   constexpr Y y = Y(); // expected-error {{no matching}}
319 #endif
320 }
321 
322 namespace dr1388 { // dr1388: 4
323   template<typename A, typename ...T> void f(T..., A); // expected-note 1+{{candidate}} expected-error 0-1{{C++11}}
324   template<typename ...T> void g(T..., int); // expected-note 1+{{candidate}} expected-error 0-1{{C++11}}
325   template<typename ...T, typename A> void h(T..., A); // expected-note 1+{{candidate}} expected-error 0-1{{C++11}}
326 
test_f()327   void test_f() {
328     f(0); // ok, trailing parameter pack deduced to empty
329     f(0, 0); // expected-error {{no matching}}
330     f<int>(0);
331     f<int>(0, 0); // expected-error {{no matching}}
332     f<int, int>(0, 0);
333     f<int, int, int>(0, 0); // expected-error {{no matching}}
334 
335     g(0);
336     g(0, 0); // expected-error {{no matching}}
337     g<>(0);
338     g<int>(0); // expected-error {{no matching}}
339     g<int>(0, 0);
340 
341     h(0);
342     h(0, 0); // expected-error {{no matching}}
343     h<int>(0, 0);
344     h<int, int>(0, 0); // expected-error {{no matching}}
345   }
346 
347   // A non-trailing parameter pack is still a non-deduced context, even though
348   // we know exactly how many arguments correspond to it.
349   template<typename T, typename U> struct pair {};
350   template<typename ...T> struct tuple { typedef char type; }; // expected-error 0-2{{C++11}}
351   template<typename ...T, typename ...U> void f_pair_1(pair<T, U>..., int); // expected-error 0-2{{C++11}} expected-note {{[with T = <int, long>]: deduced incomplete pack <(no value), (no value)> for template parameter 'U'}}
352   template<typename ...T, typename U> void f_pair_2(pair<T, char>..., U); // expected-error 0-2{{C++11}}
353   template<typename ...T, typename ...U> void f_pair_3(pair<T, U>..., tuple<U...>); // expected-error 0-2{{C++11}} expected-note {{deduced packs of different lengths for parameter 'U' (<(no value), (no value)> vs. <char>)}}
354   template<typename ...T> void f_pair_4(pair<T, char>..., T...); // expected-error 0-2{{C++11}} expected-note {{<int, long> vs. <int, long, const char *>}}
g(pair<int,char> a,pair<long,char> b,tuple<char,char> c)355   void g(pair<int, char> a, pair<long, char> b, tuple<char, char> c) {
356     f_pair_1<int, long>(a, b, 0); // expected-error {{no match}}
357     f_pair_2<int, long>(a, b, 0);
358     f_pair_3<int, long>(a, b, c);
359     f_pair_3<int, long>(a, b, tuple<char>()); // expected-error {{no match}}
360     f_pair_4<int, long>(a, b, 0, 0L);
361     f_pair_4<int, long>(a, b, 0, 0L, "foo"); // expected-error {{no match}}
362   }
363 }
364 
365 namespace dr1391 { // dr1391: partial
366   struct A {}; struct B : A {};
367   template<typename T> struct C { C(int); typename T::error error; }; // expected-error 2{{'::'}}
368   template<typename T> struct D {};
369 
370   // No deduction is performed for parameters with no deducible template-parameters, therefore types do not need to match.
371   template<typename T> void a(T, int T::*);
test_a(int A::* p)372   void test_a(int A::*p) { a(A(), p); } // ok, type of second parameter does not need to match
373 
374   namespace dr_example_1 {
375     template<typename T, typename U> void f(C<T>);
376     template<typename T> void f(D<T>);
377 
g(D<int> d)378     void g(D<int> d) {
379       f(d); // ok, first 'f' eliminated by deduction failure
380       f<int>(d); // ok, first 'f' eliminated because 'U' cannot be deduced
381     }
382   }
383 
384   namespace dr_example_2 {
385     template<typename T> typename C<T>::error f(int, T);
386     template<typename T> T f(T, T);
387 
g(A a)388     void g(A a) {
389       f(a, a); // ok, no conversion from A to int for first parameter of first candidate
390     }
391   }
392 
393   namespace std_example {
394     template<typename T> struct Z {
395       typedef typename T::x xx;
396     };
397     template<typename T> typename Z<T>::xx f(void *, T);
398     template<typename T> void f(int, T);
399     struct A {} a;
g()400     void g() { f(1, a); }
401   }
402 
403   template<typename T> void b(C<int> ci, T *p);
404   void b(...);
test_b()405   void test_b() {
406     b(0, 0); // ok, deduction fails prior to forming a conversion sequence and instantiating C<int>
407     // FIXME: The "while substituting" note should point at the overload candidate.
408     b<int>(0, 0); // expected-note {{instantiation of}} expected-note {{while substituting}}
409   }
410 
411   template<typename T> struct Id { typedef T type; };
412   template<typename T> void c(T, typename Id<C<T> >::type);
test_c()413   void test_c() {
414     // Implicit conversion sequences for dependent types are checked later.
415     c(0.0, 0); // expected-note {{instantiation of}}
416   }
417 
418   namespace partial_ordering {
419     // FIXME: Second template should be considered more specialized because non-dependent parameter is ignored.
420     template<typename T> int a(T, short) = delete; // expected-error 0-1{{extension}} expected-note {{candidate}}
421     template<typename T> int a(T*, char); // expected-note {{candidate}}
422     int test_a = a((int*)0, 0); // FIXME: expected-error {{ambiguous}}
423 
424     // FIXME: Second template should be considered more specialized:
425     // deducing #1 from #2 ignores the second P/A pair, so deduction succeeds,
426     // deducing #2 from #1 fails to deduce T, so deduction fails.
427     template<typename T> int b(T, int) = delete; // expected-error 0-1{{extension}} expected-note {{candidate}}
428     template<typename T, typename U> int b(T*, U); // expected-note {{candidate}}
429     int test_b = b((int*)0, 0); // FIXME: expected-error {{ambiguous}}
430 
431     // Unintended consequences: because partial ordering does not consider
432     // explicit template arguments, and deduction from a non-dependent type
433     // vacuously succeeds, a non-dependent template is less specialized than
434     // anything else!
435     // According to DR1391, this is ambiguous!
436     template<typename T> int c(int);
437     template<typename T> int c(T);
438     int test_c1 = c(0); // ok
439     int test_c2 = c<int>(0); // FIXME: apparently ambiguous
440   }
441 }
442 
443 namespace dr1399 { // dr1399: dup 1388
f(T...,int,T...)444   template<typename ...T> void f(T..., int, T...) {} // expected-note {{candidate}} expected-error 0-1{{C++11}}
g()445   void g() {
446     f(0);
447     f<int>(0, 0, 0);
448     f(0, 0, 0); // expected-error {{no match}}
449   }
450 }
451