xref: /llvm-project/clang/test/SemaTemplate/typename-specifier-3.cpp (revision 4848f3bf2ff5ec57a8e2b8d3676c947dcf0fd735)
1 // RUN: %clang_cc1 -fsyntax-only -verify=expected,precxx17 %std_cxx11-14 %s
2 // RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx17 %std_cxx17- %s
3 
4 // PR4364
5 template<class T> struct a { // precxx17-note {{here}}
ba6   T b() {
7     return typename T::x();
8   }
9 };
10 struct B {
11   typedef B x;
12 };
c()13 B c() {
14   a<B> x;
15   return x.b();
16 }
17 
18 // Some extra tests for invalid cases
btest219 template<class T> struct test2 { T b() { return typename T::a; } }; // expected-error{{expected '(' for function-style cast or type construction}}
btest320 template<class T> struct test3 { T b() { return typename a; } }; // expected-error{{expected a qualified name after 'typename'}} cxx17-error{{expected '(' for function-style cast or type construction}}
btest421 template<class T> struct test4 { T b() { return typename ::a; } }; // precxx17-error{{refers to non-type member}} expected-error{{expected '(' for function-style cast or type construction}}
22 
23 // PR12884
24 namespace PR12884_original {
25   template <typename T> struct A {
26     struct B {
27       template <typename U> struct X {};
28       typedef int arg;
29     };
30     struct C {
31       typedef B::X<typename B::arg> x; // precxx17-warning{{missing 'typename' prior to dependent type name B::X; implicit 'typename' is a C++20 extension}}
32     };
33   };
34 
35   template <> struct A<int>::B {
36     template <int N> struct X {};
37     static const int arg = 0;
38   };
39 
40   A<int>::C::x a;
41 }
42 namespace PR12884_half_fixed {
43   template <typename T> struct A {
44     struct B {
45       template <typename U> struct X {};
46       typedef int arg;
47     };
48     struct C {
49       typedef typename B::X<typename B::arg> x; // expected-error {{use 'template'}} expected-error {{refers to non-type}}
50     };
51   };
52 
53   template <> struct A<int>::B {
54     template <int N> struct X {};
55     static const int arg = 0; // expected-note {{here}}
56   };
57 
58   A<int>::C::x a; // expected-note {{here}}
59 }
60 namespace PR12884_fixed {
61   template <typename T> struct A {
62     struct B {
63       template <typename U> struct X {};
64       typedef int arg;
65     };
66     struct C {
67       typedef typename B::template X<B::arg> x;
68     };
69   };
70 
71   template <> struct A<int>::B {
72     template <int N> struct X {};
73     static const int arg = 0;
74   };
75 
76   A<int>::C::x a; // ok
77 }
78