clang/test/CXX/basic/basic.link/p7.cpp

   1 // RUN: %clang_cc1 -verify -std=c++1y %s
   2
   3 // Example from the standard.
   4 namespace X {
   5   void p() {
   6     q(); // expected-error {{undeclared}}
   7     extern void q();
   8   }
   9   void middle() {
  10     q(); // expected-error {{undeclared}}
  11   }
  12   void q() { /*...*/ }
  13   void bottom() {
  14     q();
  15   }
  16 }
  17 int q();
  18
  19 namespace Test1 {
  20   void f() {
  21     extern int a; // expected-note {{previous}}
  22     int g(void); // expected-note {{previous}}
  23   }
  24   double a; // expected-error {{different type: 'double' vs 'int'}}
  25   double g(); // expected-error {{differ only in their return type}}
  26 }
  27
  28 namespace Test2 {
  29   void f() {
  30     extern int a; // expected-note {{previous}}
  31     int g(void); // expected-note {{previous}}
  32   }
  33   void h() {
  34     extern double a; // expected-error {{different type: 'double' vs 'int'}}
  35     double g(void); // expected-error {{differ only in their return type}}
  36   }
  37 }
  38
  39 namespace Test3 {
  40   constexpr void (*f())() {
  41     void h();
  42     return &h;
  43   }
  44   constexpr void (*g())() {
  45     void h();
  46     return &h;
  47   }
  48   static_assert(f() == g(), "");
  49 }
  50
  51 namespace Test4 {
  52   template<typename T>
  53   constexpr void (*f())() {
  54     void h();
  55     return &h;
  56   }
  57   static_assert(f<int>() == f<char>(), "");
  58   void h();
  59   static_assert(f<int>() == &h, "");
  60 }
  61
  62 namespace Test5 {
  63   constexpr auto f() -> void (*)() {
  64     void g();
  65     struct X {
  66       friend void g();
  67       static constexpr auto h() -> void (*)() { return g; }
  68     };
  69     return X::h();
  70   }
  71   void g();
  72   static_assert(f() == g, "");
  73 }