xref: /llvm-project/clang/test/CXX/temp/temp.res/temp.local/p1.cpp (revision 11255ec7659cec933e0b0415c14d50ca80cb16cd)
1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z %s
2 
3 // C++1z [temp.local]p1:
4 //   Like normal (non-template) classes, class templates have an
5 //   injected-class-name (Clause 9). The injected-class-name can
6 //   be used as a template-name or a type-name.
7 
8 template<typename> char id;
9 
10 template<typename> struct TempType {};
11 template<template<typename> class> struct TempTemp {};
12 
13 template<typename> void use(int&); // expected-note {{invalid explicitly-specified argument}} expected-note {{no known conversion}}
14 template<template<typename> class> void use(float&); // expected-note 2{{no known conversion}}
15 template<int> void use(char&); // expected-note 2{{invalid explicitly-specified argument}}
16 
17 template<typename T> struct A {
18   template<typename> struct C {};
19   struct B : C<T> {
20     //   When it is used with a template-argument-list,
21     A<int> *aint;
22     typename B::template C<int> *cint;
23 
24     //   as a template-argument for a template template-parameter,
25     TempTemp<A> a_as_temp;
26     TempTemp<B::template C> c_as_temp;
27 
28     //   or as the final identifier in the elaborated-type-specifier of a friend
29     //   class template declaration,
30     template<typename U> friend struct A;
31     // it refers to the class template itself.
32 
33     // Otherwise, it is equivalent to the template-name followed by the
34     // template-parameters of the class template enclosed in <>.
35     A *aT;
36     typename B::C *cT;
37     TempType<A> a_as_type;
38     TempType<typename B::C> c_as_type;
39     friend struct A;
40     friend struct B::C;
41 
fA::B42     void f(T &t) {
43       use<A>(t); // expected-error {{no matching function}}
44       if constexpr (&id<T> != &id<int>)
45         use<B::template C>(t); // expected-error {{no matching function}}
46     }
47   };
48 };
49 
50 template struct A<int>;
51 template struct A<float>;
52 template struct A<char>; // expected-note {{instantiation of}}
53 
54 template <typename T> struct X0 {
55   X0();
56   ~X0();
57   X0 f(const X0&);
58 };
59 
60 // Test non-type template parameters.
61 template <int N1, const int& N2, const int* N3> struct X1 {
62   X1();
63   ~X1();
fX164   X1 f(const X1& x1a) { X1 x1b(x1a); return x1b; }
65 };
66 
67 //   When it is used with a template-argument-list, it refers to the specified
68 //   class template specialization, which could be the current specialization
69 //   or another specialization.
70 // FIXME: Test this clause.
71 
72 int i = 42;
test()73 void test() {
74   X0<int> x0; (void)x0;
75   X1<42, i, &i> x1; (void)x1;
76 }
77