gcc/testsuite/g++.dg/cpp0x/trailing1.C

   1 // Tests for late-specified return type.
   2 // { dg-options "-std=c++0x" }
   3
   4 auto f() -> int
   5 {
   6   return 0;
   7 }
   8
   9 template<class T, class U>
  10 auto add(T t, U u) -> decltype (t+u)
  11 {
  12   return t+u;
  13 }
  14
  15 template<class T, class U>
  16 decltype(T()+U()) add2(T t, U u)
  17 {
  18   return t+u;
  19 }
  20
  21 template <class T, class U>
  22 U ag (T, U)
  23 {
  24   return U();
  25 }
  26
  27 template<class T, class U>
  28 auto add3(T t, U u) -> decltype (ag(t,u))
  29 {
  30   return ag(t,u);
  31 }
  32
  33 template<class T, class U>
  34 decltype(*(T*)0+*(U*)0) add4(T t, U u)
  35 {
  36   return t+u;
  37 }
  38
  39 template <class T>
  40 struct A
  41 {
  42   T f() {}
  43   template <class U>
  44   T g() {}
  45   template <class V>
  46   struct B
  47   {
  48     int MEM;
  49   };
  50 };
  51
  52 template <class T>
  53 auto f(T* t) -> decltype (t->f())
  54 {
  55   return t->f();
  56 }
  57
  58 template <class T>
  59 auto g(T t) -> decltype (t.f())
  60 {
  61   return t.f();
  62 }
  63
  64 template <class T, class U>
  65 auto h(T t, U u) -> decltype (t.template g<U>())
  66 {
  67   return t.template g<U>();
  68 }
  69
  70 struct D { };
  71 struct C: public A<int>::B<D>
  72 {
  73 };
  74
  75 template <class T, class U, class V>
  76 auto k(T t, U u, V v) -> decltype (t.U::template B<V>::MEM)
  77 {
  78   return t.U::template B<V>::MEM;
  79 }
  80
  81 // For these two examples we can elide the 'decltype' and just mangle the type.
  82 template <class T>
  83 auto l(T t) -> decltype (t)
  84 {
  85   return t;
  86 }
  87
  88 template <class T, T u>
  89 auto m(T t) -> decltype (u)
  90 {
  91   return t;
  92 }
  93
  94 A<int> a, *p;
  95
  96 int main()
  97 {
  98   // { dg-final { scan-assembler  "_Z3addIidEDTplfp_fp0_ET_T0_" } }
  99   auto i = add(1, 2.0);
 100   // { dg-final { scan-assembler "_Z4add4IidEDTpldecvPT_Li0EdecvPT0_Li0EES0_S2_" } }
 101   auto i4 = add4(1, 2.0);
 102   // { dg-final { scan-assembler "_Z4add2IidEDTplcvT__EcvT0__EES0_S1_" } }
 103   auto i2 = add2(1, 2.0);
 104   // { dg-final { scan-assembler "_Z4add3IidEDTcl2agfp_fp0_EET_T0_" } }
 105   auto i3 = add3(1, 2.0);
 106   // { dg-final { scan-assembler "_Z1fI1AIiEEDTclptfp_1fEEPT_" } }
 107   f(p);
 108   // { dg-final { scan-assembler "_Z1gI1AIiEEDTcldtfp_1fEET_" } }
 109   g(a);
 110   // { dg-final { scan-assembler "_Z1hI1AIiEdEDTcldtfp_1gIT0_EEET_S2_" } }
 111   h(a,1.0);
 112   // { dg-final { scan-assembler "_Z1kI1C1AIiE1DEDtdtfp_srNT0_1BIT1_EE3MEMET_S4_S6_" } }
 113   k( C(), A<int>(), D() );
 114   // { dg-final { scan-assembler "_Z1lIiET_S0_" } }
 115   l(1);
 116   // { dg-final { scan-assembler "_Z1mIiLi1EET_S0_" } }
 117   m<int,1>(1);
 118 }