1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z %s
3 template<typename T, T val> struct A {};
5 template<typename T, typename U> constexpr bool is_same = false; // expected-note +{{here}}
6 template<typename T> constexpr bool is_same<T, T> = true;
9 A<const char*, "test"> a; // expected-error {{does not refer to any declaration}}
10 A<const char (&)[5], "test"> b; // expected-error {{does not refer to any declaration}}
16 A<const char*, arr> a;
17 A<const char(&)[3], arr> b;
18 A<const char*, &arr[0]> c;
19 A<const char*, &arr[1]> d; // expected-error {{refers to subobject '&arr[1]'}}
20 A<const char*, (&arr)[0]> e;
22 A<const char*, &(&x)[0]> g;
23 A<const char*, &(&x)[1]> h; // expected-error {{refers to subobject '&x + 1'}}
24 A<const char*, 0> i; // expected-error {{not allowed in a converted constant}}
25 A<const char*, nullptr> j;
33 template<typename...T> void i(T...);
34 typedef A<void (*)(), f> a;
35 typedef A<void (*)(), &f> a;
36 typedef A<void (*)(), g> b;
37 typedef A<void (*)(), &g> b;
38 typedef A<void (*)(), h> c;
39 typedef A<void (*)(), &h> c;
40 typedef A<void (*)(), i> d;
41 typedef A<void (*)(), &i> d;
42 typedef A<void (*)(), i<>> d;
43 typedef A<void (*)(), i<int>> e; // expected-error {{is not implicitly convertible}}
45 typedef A<void (*)(), 0> x; // expected-error {{not allowed in a converted constant}}
46 typedef A<void (*)(), nullptr> y;
50 A<const char*, __func__> a; // expected-error {{does not refer to any declaration}}
53 namespace LabelAddrDiff {
55 a: b: A<int, __builtin_constant_p(true) ? (__INTPTR_TYPE__)&&b - (__INTPTR_TYPE__)&&a : 0> s; // expected-error {{label address difference}}
61 constexpr S &addr(S &&s) { return s; }
62 A<S &, addr({})> a; // expected-error {{constant}} expected-note 2{{temporary}}
63 A<S *, &addr({})> b; // expected-error {{constant}} expected-note 2{{temporary}}
64 A<int &, addr({}).n> c; // expected-error {{constant}} expected-note 2{{temporary}}
65 A<int *, &addr({}).n> d; // expected-error {{constant}} expected-note 2{{temporary}}
68 namespace std { struct type_info; }
71 A<const std::type_info&, typeid(int)> a; // expected-error {{does not refer to any declaration}}
72 A<const std::type_info*, &typeid(int)> b; // expected-error {{does not refer to any declaration}}
79 struct E : C, D { int e; };
81 constexpr int B::*b = &B::b;
82 constexpr int C::*cb = b;
83 constexpr int D::*db = b;
84 constexpr int E::*ecb = cb; // expected-note +{{here}}
85 constexpr int E::*edb = db; // expected-note +{{here}}
87 constexpr int E::*e = &E::e;
88 constexpr int D::*de = (int D::*)e;
89 constexpr int C::*ce = (int C::*)e;
90 constexpr int B::*bde = (int B::*)de; // expected-note +{{here}}
91 constexpr int B::*bce = (int B::*)ce; // expected-note +{{here}}
93 // FIXME: This should all be accepted, but we don't yet have a representation
94 // nor mangling for this form of template argument.
95 using Ab = A<int B::*, b>;
96 using Ab = A<int B::*, &B::b>;
97 using Abce = A<int B::*, bce>; // expected-error {{not supported}}
98 using Abde = A<int B::*, bde>; // expected-error {{not supported}}
99 static_assert(!is_same<Ab, Abce>, ""); // expected-error {{undeclared}} expected-error {{must be a type}}
100 static_assert(!is_same<Ab, Abde>, ""); // expected-error {{undeclared}} expected-error {{must be a type}}
101 static_assert(!is_same<Abce, Abde>, ""); // expected-error 2{{undeclared}} expected-error {{must be a type}}
102 static_assert(is_same<Abce, A<int B::*, (int B::*)(int C::*)&E::e>, ""); // expected-error {{undeclared}} expected-error {{not supported}}
104 using Ae = A<int E::*, e>;
105 using Ae = A<int E::*, &E::e>;
106 using Aecb = A<int E::*, ecb>; // expected-error {{not supported}}
107 using Aedb = A<int E::*, edb>; // expected-error {{not supported}}
108 static_assert(!is_same<Ae, Aecb>, ""); // expected-error {{undeclared}} expected-error {{must be a type}}
109 static_assert(!is_same<Ae, Aedb>, ""); // expected-error {{undeclared}} expected-error {{must be a type}}
110 static_assert(!is_same<Aecb, Aedb>, ""); // expected-error 2{{undeclared}} expected-error {{must be a type}}
111 static_assert(is_same<Aecb, A<int E::*, (int E::*)(int C::*)&B::b>, ""); // expected-error {{undeclared}} expected-error {{not supported}}
113 using An = A<int E::*, nullptr>;
114 using A0 = A<int E::*, (int E::*)0>;
115 static_assert(is_same<An, A0>);
118 namespace DeduceDifferentType {
119 template<int N> struct A {};
120 template<long N> int a(A<N>); // expected-note {{does not have the same type}}
121 int a_imp = a(A<3>()); // expected-error {{no matching function}}
122 int a_exp = a<3>(A<3>());
124 template<decltype(nullptr)> struct B {};
125 template<int *P> int b(B<P>); // expected-error {{value of type 'int *' is not implicitly convertible to 'decltype(nullptr)'}}
126 int b_imp = b(B<nullptr>()); // expected-error {{no matching function}}
127 int b_exp = b<nullptr>(B<nullptr>()); // expected-error {{no matching function}}
129 struct X { constexpr operator int() { return 0; } } x;
130 template<X &> struct C {};
131 template<int N> int c(C<N>); // expected-error {{value of type 'int' is not implicitly convertible to 'DeduceDifferentType::X &'}}
132 int c_imp = c(C<x>()); // expected-error {{no matching function}}
133 int c_exp = c<x>(C<x>()); // expected-error {{no matching function}}
136 struct Y { constexpr operator Z&(); } y;
137 struct Z { constexpr operator Y&() { return y; } } z;
138 constexpr Y::operator Z&() { return z; }
139 template<Y &> struct D {};
140 template<Z &z> int d(D<z>); // expected-note {{couldn't infer template argument 'z'}}
141 int d_imp = d(D<y>()); // expected-error {{no matching function}}
142 int d_exp = d<y>(D<y>());
145 namespace DeclMatch {
146 template<typename T, T> int f();
147 template<typename T> class X { friend int f<T, 0>(); static int n; };
148 template<typename T, T> int f() { return X<T>::n; }
149 int k = f<int, 0>(); // ok, friend
154 template<E> void f();
155 template<int> void f(int);
156 template<> void f<e>() {}
162 template<auto x> constexpr auto constant = x; // expected-note {{declared here}}
164 auto v1 = constant<5>;
165 auto v2 = constant<true>;
166 auto v3 = constant<'a'>;
167 auto v4 = constant<2.5>; // expected-error {{cannot have type 'double'}}
169 using T1 = decltype(v1);
171 using T2 = decltype(v2);
173 using T3 = decltype(v3);
177 template<auto v> class B { };
178 template<auto* p> class B<p> { }; // expected-note {{matches}}
179 template<auto** pp> class B<pp> { };
180 template<auto* p0> int &f(B<p0> b); // expected-note {{candidate}}
181 template<auto** pp0> float &f(B<pp0> b); // expected-note {{candidate}}
185 float &s = f(B<&b>());
187 // pointers to members
188 template<typename T, auto *T::*p> struct B<p> {};
189 template<typename T, auto **T::*p> struct B<p> {};
190 template<typename T, auto *T::*p0> char &f(B<p0> b); // expected-note {{candidate}}
191 template<typename T, auto **T::*pp0> short &f(B<pp0> b); // expected-note {{candidate}}
193 struct X { int n; int *p; int **pp; typedef int a, b; };
194 auto t = f(B<&X::n>()); // expected-error {{no match}}
195 char &u = f(B<&X::p>());
196 short &v = f(B<&X::pp>());
198 // A case where we need to do auto-deduction, and check whether the
199 // resulting dependent types match during partial ordering. These
200 // templates are not ordered due to the mismatching function parameter.
201 template<typename T, auto *(*f)(T, typename T::a)> struct B<f> {}; // expected-note {{matches}}
202 template<typename T, auto **(*f)(T, typename T::b)> struct B<f> {}; // expected-note {{matches}}
204 B<&g> bg; // expected-error {{ambiguous}}
208 // chained template argument deduction
209 template<long n> struct C { };
210 template<class T> struct D;
211 template<class T, T n> struct D<C<n>>
216 using DQ = D<C<short(2)>>::Q;
218 // chained template argument deduction from an array bound
219 template<typename T> struct E;
220 template<typename T, T n> struct E<int[n]> {
223 using EQ = E<int[short(42)]>::Q;
224 using EQ = decltype(sizeof 0);
226 template<int N> struct F;
227 template<typename T, T N> int foo(F<N> *) = delete; // expected-note {{explicitly deleted}}
228 void foo(void *); // expected-note {{candidate function}}
230 foo(p); // expected-error {{deleted function}}
234 namespace ArrayToPointer {
235 constexpr char s[] = "test";
236 template<const auto* p> struct S { };
240 namespace DecltypeAuto {
241 template<auto v> struct A { };
242 template<decltype(auto) v> struct DA { };
243 template<auto&> struct R { };
245 auto n = 0; // expected-note + {{declared here}}
246 A<n> a; // expected-error {{not a constant}} expected-note {{non-const variable 'n'}}
247 DA<n> da1; // expected-error {{not a constant}} expected-note {{non-const variable 'n'}}
252 namespace Decomposition {
253 // Types of deduced non-type template arguments must match exactly, so
254 // partial ordering fails in both directions here.
255 template<auto> struct Any;
256 template<int N> struct Any<N> { typedef int Int; }; // expected-note 3{{match}}
257 template<short N> struct Any<N> { typedef int Short; }; // expected-note 3{{match}}
258 Any<0>::Int is_int; // expected-error {{ambiguous}}
259 Any<(short)0>::Short is_short; // expected-error {{ambiguous}}
260 Any<(char)0>::Short is_char; // expected-error {{ambiguous}}
262 template<int, auto> struct NestedAny;
263 template<auto N> struct NestedAny<0, N>; // expected-note 3{{match}}
264 template<int N> struct NestedAny<0, N> { typedef int Int; }; // expected-note 3{{match}}
265 template<short N> struct NestedAny<0, N> { typedef int Short; }; // expected-note 3{{match}}
266 NestedAny<0, 0>::Int nested_int; // expected-error {{ambiguous}}
267 NestedAny<0, (short)0>::Short nested_short; // expected-error {{ambiguous}}
268 NestedAny<0, (char)0>::Short nested_char; // expected-error {{ambiguous}}
270 double foo(int, bool);
271 template<auto& f> struct fn_result_type;
273 template<class R, class... Args, R (& f)(Args...)>
274 struct fn_result_type<f>
279 using R1 = fn_result_type<foo>::type;
282 template<int, auto &f> struct fn_result_type_partial_order;
283 template<auto &f> struct fn_result_type_partial_order<0, f>;
284 template<class R, class... Args, R (& f)(Args...)>
285 struct fn_result_type_partial_order<0, f> {};
286 fn_result_type_partial_order<0, foo> frtpo;
290 template<auto... vs> struct value_list { };
292 using size_t = decltype(sizeof 0);
293 template<size_t n, class List> struct nth_element;
294 template<size_t n, class List> constexpr auto nth_element_v = nth_element<n, List>::value;
296 template<size_t n, auto v0, auto... vs>
297 struct nth_element<n, value_list<v0, vs...>>
299 static constexpr auto value = nth_element<n - 1, value_list<vs...>>::value;
301 template<auto v0, auto... vs>
302 struct nth_element<0, value_list<v0, vs...>>
304 static constexpr auto value = v0;
307 static_assert(nth_element_v<2, value_list<'a', 27U, false>> == false, "value mismatch");
312 template<typename T> struct A {
313 template<auto X> struct B;
314 template<auto *P> struct B<P>;
315 template<auto **P> struct B<P> { using pointee = decltype(+**P); };
316 template<auto (*P)(T)> struct B<P> { using param = T; };
317 template<typename U, auto (*P)(T, U)> struct B<P> { using param2 = U; };
323 using Int = A<int>::B<&n>::pointee;
326 using Int = A<int>::B<&f>::param;
329 using Int = A<int>::B<&g>::param2;