gcc/testsuite/g++.dg/cpp0x/decltype4.C

   1 // { dg-do compile { target c++11 } }
   2
   3 template<typename T, typename U>
   4 struct is_same
   5 {
   6   static const bool value = false;
   7 };
   8
   9 template<typename T>
  10 struct is_same<T, T>
  11 {
  12   static const bool value = true;
  13 };
  14
  15 #define CHECK_DECLTYPE(DECLTYPE,RESULT) \
  16   static_assert(is_same< DECLTYPE , RESULT >::value, #DECLTYPE " should be " #RESULT)
  17
  18 struct A {
  19   int x;
  20   int& y;
  21   int foo(char);
  22   int& bar() const;
  23 };
  24
  25 CHECK_DECLTYPE(decltype(&A::x), int A::*);
  26 decltype(&A::y) Ay; // { dg-error "14:cannot create pointer to reference member|invalid type" }
  27 CHECK_DECLTYPE(decltype(&A::foo), int (A::*) (char));
  28 CHECK_DECLTYPE(decltype(&A::bar), int& (A::*) () const);
  29
  30 CHECK_DECLTYPE(decltype("decltype"), const char(&)[9]);
  31 CHECK_DECLTYPE(decltype(1), int);
  32
  33 int an_int = 5;
  34 int& i = an_int;
  35 const int j = an_int;
  36
  37 CHECK_DECLTYPE(decltype(i)&, int&);
  38 CHECK_DECLTYPE(const decltype(j), const int);
  39
  40 int foo();
  41 CHECK_DECLTYPE(decltype(foo()), int);
  42 float& bar(int);
  43 CHECK_DECLTYPE(decltype (bar(1)), float&);
  44 const A bar();
  45 CHECK_DECLTYPE(decltype (bar()), const A);
  46 const A& bar2();
  47 CHECK_DECLTYPE(decltype (bar2()), const A&);
  48
  49 void wibble() {
  50   CHECK_DECLTYPE(decltype(1+2), int);
  51   int* p;
  52   CHECK_DECLTYPE(decltype(*p), int&);
  53   int a[10];
  54   CHECK_DECLTYPE(decltype(a[3]), int&);
  55   int i; int& j = i;
  56   CHECK_DECLTYPE(decltype (i = 5), int&);
  57   CHECK_DECLTYPE(decltype (j = 5), int&);
  58
  59   CHECK_DECLTYPE(decltype (++i), int&);
  60   CHECK_DECLTYPE(decltype (i++), int);
  61 }
  62
  63 struct B {
  64   B () : bit(), cbit() {}
  65   int bit : 2;
  66   const int cbit : 3;
  67
  68   void foo()
  69   {
  70     CHECK_DECLTYPE(decltype(bit), int);
  71     CHECK_DECLTYPE(decltype((bit)), int&);
  72     CHECK_DECLTYPE(decltype(cbit), const int);
  73     CHECK_DECLTYPE(decltype((cbit)), const int&);
  74   }
  75 };
  76
  77 B b;
  78 const B& bc = b;
  79 CHECK_DECLTYPE(decltype(b.bit), int);
  80 CHECK_DECLTYPE(decltype(bc.bit), int);
  81 CHECK_DECLTYPE(decltype((b.bit)), int&);
  82 CHECK_DECLTYPE(decltype((bc.bit)), const int&);