119 lines · cpp
1// RUN: %clang_cc1 -std=c++17 -verify=expected,cxx17 %s2// RUN: %clang_cc1 -std=c++20 -verify=expected,cxx20 %s3 4namespace pr41427 {5 template <typename T> class A {6 public:7 A(void (*)(T)) {}8 };9 10 void D(int) {}11 12 void f() {13 A a(&D);14 using T = decltype(a);15 using T = A<int>;16 }17}18 19namespace Access {20 struct B {21 protected:22 struct type {};23 };24 template<typename T> struct D : B { // expected-note {{not viable}} \25 expected-note {{implicit deduction guide declared as 'template <typename T> D(Access::D<T>) -> Access::D<T>'}}26 D(T, typename T::type); // expected-note {{private member}} \27 // expected-note {{implicit deduction guide declared as 'template <typename T> D(T, typename T::type) -> Access::D<T>'}}28 };29 D b = {B(), {}};30 31 class X {32 using type = int;33 };34 D x = {X(), {}}; // expected-error {{no viable constructor or deduction guide}}35 36 // Once we implement proper support for dependent nested name specifiers in37 // friends, this should still work.38 class Y {39 template <typename T> friend D<T>::D(T, typename T::type); // expected-warning {{dependent nested name specifier}}40 struct type {};41 };42 D y = {Y(), {}};43 44 class Z {45 template <typename T> friend class D;46 struct type {};47 };48 D z = {Z(), {}};49}50 51namespace GH69987 {52template<class> struct X {};53template<class = void> struct X;54X x;55 56template<class T, class B> struct Y { Y(T); };57template<class T, class B=void> struct Y ;58Y y(1);59}60 61namespace NoCrashOnGettingDefaultArgLoc {62template <typename>63class A {64 A(int = 1); // expected-note {{candidate template ignored: couldn't infer template argumen}} \65 // expected-note {{implicit deduction guide declared as 'template <typename> D(int = <null expr>) -> NoCrashOnGettingDefaultArgLoc::D<type-parameter-0-0>'}}66};67class C : A<int> {68 using A::A;69};70template <typename>71class D : C { // expected-note {{candidate function template not viable: requires 1 argument}} \72 expected-note {{implicit deduction guide declared as 'template <typename> D(NoCrashOnGettingDefaultArgLoc::D<type-parameter-0-0>) -> NoCrashOnGettingDefaultArgLoc::D<type-parameter-0-0>'}}73 using C::C;74};75D abc; // expected-error {{no viable constructor or deduction guide}}76}77 78namespace AsValueParameter {79 namespace foo {80 // cxx17-note@+2 {{template is declared here}}81 // cxx20-note@+1 {{'A<int>' is not literal because it is not an aggregate and has no constexpr constructors other than copy or move constructors}}82 template <class> struct A {83 A();84 };85 }86 template <foo::A> struct B {}; // expected-note {{template parameter is declared here}}87 // cxx17-error@-1 {{use of class template 'foo::A' requires template arguments; argument deduction not allowed in template parameter}}88 89 template struct B<foo::A<int>{}>;90 // cxx17-error@-1 {{value of type 'foo::A<int>' is not implicitly convertible to 'int'}}91 // cxx20-error@-2 {{non-type template parameter has non-literal type 'foo::A<int>' (aka 'AsValueParameter::foo::A<int>')}}92} // namespace AsValueParameter93 94namespace ConvertDeducedTemplateArgument {95 namespace A {96 template <class> struct B {};97 }98 99 template <template <class> class TT1> struct C {100 C(TT1<int>);101 };102 103 template <template <class> class TT2> using D = TT2<int>;104 105 auto x = C(D<A::B>());106}107 108namespace pr165560 {109template <class T, class> struct S {110 using A = T;111 template <class> struct I { // expected-note{{candidate function template not viable: requires 1 argument, but 0 were provided}} \112 // expected-note{{implicit deduction guide declared as 'template <class> I(pr165560::S<int, int>::I<type-parameter-0-0>) -> pr165560::S<int, int>::I<type-parameter-0-0>'}}113 I(typename A::F) {} // expected-error{{type 'A' (aka 'int') cannot be used prior to '::' because it has no members}}114 };115};116S<int, int>::I i; // expected-error{{no viable constructor or deduction guide for deduction of template arguments of 'S<int, int>::I'}} \117 // expected-note{{while building implicit deduction guide first needed here}}118}119