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

   1 // { dg-do "compile" }
   2 // { dg-options "-std=gnu++0x" }
   3
   4 template<typename T, typename U>
   5 struct is_same
   6 {
   7   static const bool value = false;
   8 };
   9
  10 template<typename T>
  11 struct is_same<T, T>
  12 {
  13   static const bool value = true;
  14 };
  15
  16 #define CHECK_DECLTYPE(DECLTYPE,RESULT) \
  17   static_assert(is_same< DECLTYPE , RESULT >::value, #DECLTYPE " should be " #RESULT)
  18
  19 struct A {
  20   int x;
  21   int& y;
  22   int foo(char);
  23   int& bar() const;
  24 };
  25
  26 CHECK_DECLTYPE(decltype(&A::x), int A::*);
  27 decltype(&A::y) Ay; // { dg-error "cannot create pointer to reference member|invalid type" }
  28 CHECK_DECLTYPE(decltype(&A::foo), int (A::*) (char));
  29 CHECK_DECLTYPE(decltype(&A::bar), int& (A::*) () const);
  30
  31 CHECK_DECLTYPE(decltype("decltype"), const char(&)[9]);
  32 CHECK_DECLTYPE(decltype(1), int);
  33
  34 int an_int = 5;
  35 int& i = an_int;
  36 const int j = an_int;
  37
  38 CHECK_DECLTYPE(decltype(i)&, int&);
  39 CHECK_DECLTYPE(const decltype(j), const int);
  40
  41 int foo();
  42 CHECK_DECLTYPE(decltype(foo()), int);
  43 float& bar(int);
  44 CHECK_DECLTYPE(decltype (bar(1)), float&);
  45 const A bar();
  46 CHECK_DECLTYPE(decltype (bar()), const A);
  47 const A& bar2();
  48 CHECK_DECLTYPE(decltype (bar2()), const A&);
  49
  50 void wibble() {
  51   CHECK_DECLTYPE(decltype(1+2), int);
  52   int* p;
  53   CHECK_DECLTYPE(decltype(*p), int&);
  54   int a[10];
  55   CHECK_DECLTYPE(decltype(a[3]), int&);
  56   int i; int& j = i;
  57   CHECK_DECLTYPE(decltype (i = 5), int&);
  58   CHECK_DECLTYPE(decltype (j = 5), int&);
  59
  60   CHECK_DECLTYPE(decltype (++i), int&);
  61   CHECK_DECLTYPE(decltype (i++), int);
  62 }
  63
  64 struct B {
  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&);