clang/test/SemaCXX/overload-template.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -std=c++23 -verify -fsyntax-only %s
   3
   4 enum copy_traits { movable = 1 };
   5
   6 template <int>
   7 struct optional_ctor_base {};
   8 template <typename T>
   9 struct ctor_copy_traits {
  10   // this would produce a c++98-compat warning, which would erroneously get the
  11   // no-matching-function-call error's notes attached to it (or suppress those
  12   // notes if this diagnostic was suppressed, as it is in this case)
  13   static constexpr int traits = copy_traits::movable;
  14 };
  15 template <typename T>
  16 struct optional : optional_ctor_base<ctor_copy_traits<T>::traits> {
  17   template <typename U>
  18   constexpr optional(U&& v);
  19 };
  20 struct A {};
  21 struct XA {
  22   XA(const A&);
  23 };
  24 struct B {};
  25 struct XB {
  26   XB(const B&);
  27   XB(const optional<B>&);
  28 };
  29 struct YB : XB {
  30   using XB::XB;
  31 };
  32 void InsertRow(const XA&, const YB&); // expected-note {{candidate function not viable: no known conversion from 'int' to 'const XA' for 1st argument}}
  33 void ReproducesBugSimply() {
  34   InsertRow(3, B{}); // expected-error {{no matching function for call to 'InsertRow'}}
  35 }
  36
  37 #if __cplusplus >= 202302L
  38 namespace overloadCheck{
  39   template<typename T>
  40   concept AlwaysTrue = true;
  41
  42   struct S {
  43     int f(AlwaysTrue auto) { return 1; }
  44     void f(this S&&, auto) {}
  45
  46     void g(auto) {}
  47     int g(this S&&,AlwaysTrue auto) {return 1;}
  48
  49     int h(AlwaysTrue auto) { return 1; } //expected-note {{previous definition is here}}
  50     int h(this S&&,AlwaysTrue auto) { // expected-error {{class member cannot be redeclared}}
  51       return 1;
  52     }
  53   };
  54
  55   int main() {
  56     int x = S{}.f(0);
  57     int y = S{}.g(0);
  58   }
  59 }
  60 #endif
  61
  62 namespace GH93076 {
  63 template <typename ...a> int b(a..., int); // expected-note-re 3 {{candidate function template not viable: no known conversion from 'int ()' to 'int' for {{.*}} argument}}
  64 int d() {
  65   (void)b<int, int>(0, 0, d); // expected-error {{no matching function for call to 'b'}}
  66   (void)b<int, int>(0, d, 0); // expected-error {{no matching function for call to 'b'}}
  67   (void)b<int, int>(d, 0, 0); // expected-error {{no matching function for call to 'b'}}
  68   return 0;
  69  }
  70 }