xref: /aosp_15_r20/external/clang/test/SemaTemplate/pack-deduction.cpp (revision 67e74705e28f6214e480b399dd47ea732279e315)
1*67e74705SXin Li // RUN: %clang_cc1 -std=c++11 -verify %s
2*67e74705SXin Li 
3*67e74705SXin Li template<typename ...T> struct X {};
4*67e74705SXin Li 
5*67e74705SXin Li template<typename T, typename U> struct P {};
6*67e74705SXin Li 
7*67e74705SXin Li namespace Nested {
8*67e74705SXin Li   template<typename ...T> int f1(X<T, T...>... a); // expected-note +{{conflicting types for parameter 'T'}}
9*67e74705SXin Li   template<typename ...T> int f2(P<X<T...>, T> ...a); // expected-note +{{conflicting types for parameter 'T'}}
10*67e74705SXin Li 
11*67e74705SXin Li   int a1 = f1(X<int, int, double>(), X<double, int, double>());
12*67e74705SXin Li   int a2 = f1(X<int, int>());
13*67e74705SXin Li   int a3 = f1(X<int>(), X<double>()); // expected-error {{no matching}}
14*67e74705SXin Li   int a4 = f1(X<int, int>(), X<int>()); // expected-error {{no matching}}
15*67e74705SXin Li   int a5 = f1(X<int>(), X<int, int>()); // expected-error {{no matching}}
16*67e74705SXin Li   int a6 = f1(X<int, int, int>(), X<int, int, int>(), X<int, int, int, int>()); // expected-error {{no matching}}
17*67e74705SXin Li 
18*67e74705SXin Li   int b1 = f2(P<X<int, double>, int>(), P<X<int, double>, double>());
19*67e74705SXin Li   int b2 = f2(P<X<int, double>, int>(), P<X<int, double>, double>(), P<X<int, double>, char>()); // expected-error {{no matching}}
20*67e74705SXin Li }
21*67e74705SXin Li 
22*67e74705SXin Li namespace PR14841 {
23*67e74705SXin Li   template<typename T, typename U> struct A {};
24*67e74705SXin Li   template<typename ...Ts> void f(A<Ts...>); // expected-note {{substitution failure [with Ts = <char, short, int>]: too many template arg}}
25*67e74705SXin Li 
g(A<char,short> a)26*67e74705SXin Li   void g(A<char, short> a) {
27*67e74705SXin Li     f(a);
28*67e74705SXin Li     f<char>(a);
29*67e74705SXin Li     f<char, short>(a);
30*67e74705SXin Li     f<char, short, int>(a); // expected-error {{no matching function}}
31*67e74705SXin Li   }
32*67e74705SXin Li }
33*67e74705SXin Li 
34*67e74705SXin Li namespace RetainExprPacks {
35*67e74705SXin Li   int f(int a, int b, int c);
36*67e74705SXin Li   template<typename ...Ts> struct X {};
37*67e74705SXin Li   template<typename ...Ts> int g(X<Ts...>, decltype(f(Ts()...)));
38*67e74705SXin Li   int n = g<int, int>(X<int, int, int>(), 0);
39*67e74705SXin Li }
40*67e74705SXin Li 
41*67e74705SXin Li namespace PR14615 {
42*67e74705SXin Li   namespace comment0 {
43*67e74705SXin Li     template <class A, class...> struct X {};
44*67e74705SXin Li     template <class... B> struct X<int, B...> {
45*67e74705SXin Li       typedef int type;
46*67e74705SXin Li       struct valid {};
47*67e74705SXin Li     };
48*67e74705SXin Li     template <typename A, typename... B, typename T = X<A, B...>,
49*67e74705SXin Li               typename = typename T::valid>
50*67e74705SXin Li     typename T::type check(int);
51*67e74705SXin Li     int i = check<int, char>(1);
52*67e74705SXin Li   }
53*67e74705SXin Li 
54*67e74705SXin Li   namespace comment2 {
55*67e74705SXin Li     template <class...> struct X;
56*67e74705SXin Li     template <typename... B, typename X<B...>::type I = 0>
57*67e74705SXin Li     char check(B...); // expected-note {{undefined template 'PR14615::comment2::X<char, int>'}}
f()58*67e74705SXin Li     void f() { check<char>(1, 2); } // expected-error {{no matching function}}
59*67e74705SXin Li   }
60*67e74705SXin Li 
61*67e74705SXin Li   namespace comment3 {
62*67e74705SXin Li     template <class...> struct X;
63*67e74705SXin Li     template <typename... B, typename X<B...>::type I = (typename X<B...>::type)0>
64*67e74705SXin Li     char check(B...); // expected-note {{undefined template 'PR14615::comment3::X<char, int>'}}
f()65*67e74705SXin Li     void f() { check<char>(1, 2); } // expected-error {{no matching function}}
66*67e74705SXin Li   }
67*67e74705SXin Li }
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