1 // RUN: %clang_cc1 -verify -std=c++11 %s
2 
3 namespace RedeclAliasTypedef {
4   template<typename U> using T = int;
5   template<typename U> using T = int;
6   template<typename U> using T = T<U>;
7 }
8 
9 namespace IllegalTypeIds {
10   template<typename U> using A = void(int n = 0); // expected-error {{default arguments can only be specified for parameters in a function declaration}}
11   template<typename U> using B = inline void(int n); // expected-error {{type name does not allow function specifier}}
12   template<typename U> using C = virtual void(int n); // expected-error {{type name does not allow function specifier}}
13   template<typename U> using D = explicit void(int n); // expected-error {{type name does not allow function specifier}}
14   template<typename U> using E = void(int n) throw(); // expected-error {{exception specifications are not allowed in type aliases}}
15   template<typename U> using F = void(*)(int n) &&; // expected-error {{pointer to function type cannot have '&&' qualifier}}
16   template<typename U> using G = __thread void(int n); // expected-error {{type name does not allow storage class to be specified}}
17   template<typename U> using H = constexpr int; // expected-error {{type name does not allow constexpr specifier}}
18 
19   template<typename U> using Y = void(int n); // ok
20   template<typename U> using Z = void(int n) &&; // ok
21 }
22 
23 namespace IllegalSyntax {
24   template<typename Z> using ::T = void(int n); // expected-error {{name defined in alias declaration must be an identifier}}
25   template<typename Z> using operator int = void(int n); // expected-error {{name defined in alias declaration must be an identifier}}
26   template<typename Z> using typename U = void; // expected-error {{name defined in alias declaration must be an identifier}}
27   template<typename Z> using typename ::V = void(int n); // expected-error {{name defined in alias declaration must be an identifier}}
28   template<typename Z> using typename ::operator bool = void(int n); // expected-error {{name defined in alias declaration must be an identifier}}
29 }
30 
31 namespace VariableLengthArrays {
32   template<typename Z> using T = int[42]; // ok
33 
34   int n = 32;
35   template<typename Z> using T = int[n]; // expected-error {{variable length array declaration not allowed at file scope}}
36 
37   const int m = 42;
38   template<typename Z> using U = int[m]; // expected-note {{previous definition}}
39   template<typename Z> using U = int[42]; // ok
40   template<typename Z> using U = int; // expected-error {{type alias template redefinition with different types ('int' vs 'int [42]')}}
41 }
42 
43 namespace RedeclFunc {
44   int f(int, char**);
45   template<typename Z> using T = int;
46   T<char> f(int, char **); // ok
47 }
48 
49 namespace LookupFilter {
50   namespace N { template<typename U> using S = int; }
51   using namespace N;
52   template<typename U> using S = S<U>*; // ok
53 }
54 
55 namespace InFunctions {
56   template<typename...T> struct S0 {
57     template<typename Z> using U = T*; // expected-error {{declaration type contains unexpanded parameter pack 'T'}}
58     U<char> u;
59   };
60 
61   template<typename Z> using T1 = int;
62   template<typename Z> using T2 = int[-1]; // expected-error {{array size is negative}}
63   template<typename...T> struct S3 { // expected-note {{template parameter is declared here}}
64     template<typename Z> using T = int; // expected-error {{declaration of 'T' shadows template parameter}}
65   };
66   template<typename Z> using Z = Z;
67 }
68 
69 namespace ClassNameRedecl {
70   class C0 {
71     // FIXME: this diagnostic is pretty poor
72     template<typename U> using C0 = int; // expected-error {{name defined in alias declaration must be an identifier}}
73   };
74   class C1 {
75     // FIXME: this diagnostic is pretty poor
76     template<typename U> using C1 = C1; // expected-error {{name defined in alias declaration must be an identifier}}
77   };
78   class C2 {
79     template<typename U> using C0 = C1; // ok
80   };
81   template<typename...T> class C3 {
82     template<typename U> using f = T; // expected-error {{declaration type contains unexpanded parameter pack 'T'}}
83   };
84   template<typename T> class C4 { // expected-note {{template parameter is declared here}}
85     template<typename U> using T = int; // expected-error {{declaration of 'T' shadows template parameter}}
86   };
87   class C5 {
88     class c; // expected-note {{previous definition}}
89     template<typename U> using c = int; // expected-error {{redefinition of 'c' as different kind of symbol}}
90     class d; // expected-note {{previous definition}}
91     template<typename U> using d = d; // expected-error {{redefinition of 'd' as different kind of symbol}}
92   };
93   class C6 {
94     class c { template<typename U> using C6 = int; }; // ok
95   };
96 }
97 
98 class CtorDtorName {
99   template<typename T> using X = CtorDtorName;
100   X<int>(); // expected-error {{expected member name}}
101   ~X<int>(); // expected-error {{destructor cannot be declared using a type alias}}
102 };
103 
104 namespace TagName {
105   template<typename Z> using S = struct { int n; }; // expected-error {{can not be defined}}
106   template<typename Z> using T = class { int n; }; // expected-error {{can not be defined}}
107   template<typename Z> using U = enum { a, b, c }; // expected-error {{can not be defined}}
108   template<typename Z> using V = struct V { int n; }; // expected-error {{'TagName::V' can not be defined in a type alias template}}
109 }
110 
111 namespace StdExample {
112   template<typename T, typename U> struct pair;
113 
114   template<typename T> using handler_t = void (*)(T);
115   extern handler_t<int> ignore;
116   extern void (*ignore)(int);
117   // FIXME: we recover as if cell is an undeclared variable. the diagnostics are terrible!
118   template<typename T> using cell = pair<T*, cell<T>*>; // expected-error {{use of undeclared identifier 'cell'}} \
119                                                            expected-error {{'T' does not refer to a value}} \
120                                                            expected-note {{declared here}} \
121                                                            expected-error {{expected ';' after alias declaration}}
122 }
123 
124 namespace Access {
125   class C0 {
126     template<typename Z> using U = int; // expected-note {{declared private here}}
127   };
128   C0::U<int> v; // expected-error {{'U' is a private member}}
129   class C1 {
130   public:
131     template<typename Z> using U = int;
132   };
133   C1::U<int> w; // ok
134 }
135 
136 namespace VoidArg {
137   template<typename Z> using V = void;
138   V<int> f(int); // ok
139   V<char> g(V<double>); // expected-error {{empty parameter list defined with a type alias of 'void' not allowed}}
140 }
141 
142 namespace Curried {
143   template<typename T, typename U> struct S;
144   template<typename T> template<typename U> using SS = S<T, U>; // expected-error {{extraneous template parameter list in alias template declaration}}
145 }
146 
147 // PR12647
148 namespace SFINAE {
149   template<bool> struct enable_if; // expected-note 2{{here}}
150   template<> struct enable_if<true> { using type = void; };
151 
152   template<typename T> struct is_enum { static constexpr bool value = __is_enum(T); };
153 
154   template<typename T> using EnableIf = typename enable_if<T::value>::type; // expected-error {{undefined template}}
155   template<typename T> using DisableIf = typename enable_if<!T::value>::type; // expected-error {{undefined template}}
156 
157   template<typename T> EnableIf<is_enum<T>> f();
158   template<typename T> DisableIf<is_enum<T>> f();
159 
160   enum E { e };
161 
162   int main() {
163     f<int>();
164     f<E>();
165   }
166 
167   template<typename T, typename U = EnableIf<is_enum<T>>> struct fail1 {}; // expected-note {{here}}
168   template<typename T> struct fail2 : DisableIf<is_enum<T>> {}; // expected-note {{here}}
169 
170   fail1<int> f1; // expected-note {{here}}
171   fail2<E> f2; // expected-note {{here}}
172 }
173