gcc/testsuite/g++.dg/cpp1y/lambda-generic-udt.C

   1 // Ensure that generic lambdas properly construct and destroy user types.
   2 // { dg-options "-DUSE_AUTO_SYNTAX" }
   3 // { dg-do run { target c++14 } }
   4
   5 int i = 3;
   6
   7 struct S
   8 {
   9   S () { ++i; }
  10   S (S const&) { ++i; }
  11   S (S&& old) { old.shadow = true; i += 2; }
  12   ~S () { if (shadow) i -= 2; else --i; }
  13
  14   bool shadow = false;
  15 };
  16
  17 extern "C" void printf(...);
  18 #define assert(e) if (e); else \
  19                  printf ("%s:%d: !(%s)\n", __FILE__, __LINE__, #e), __builtin_abort ();
  20
  21 int main ()
  22 {
  23   assert (i == 3);
  24   {
  25     S s; assert (i == 4);
  26
  27     #if USE_AUTO_SYNTAX
  28     auto byref = [] (auto& r)                   { (void) r; };
  29     auto bycref = [] (auto const& r)            { (void) r; };
  30     auto byval = [] (auto v, auto const x)      { assert (i == x); (void) v; };
  31     auto byrval = [] (auto&& r, auto const x)   { S steal (static_cast<S&&>(r));
  32                                                                                            assert (i == x); };
  33
  34     #elif USE_EXPLICIT_TEMPLATE_SYNTAX
  35     auto byref = [] <typename T> (T& r)         { (void) r; };
  36     auto bycref = [] <typename T> (T const& r)  { (void) r; };
  37     auto byval = [] <typename T, typename I>
  38                                      (T v, I const x)                            { assert (i == x); (void) v; };
  39     auto byrval = [] <typename T, typename I>
  40                                       (T&& r, I const x)                                 { S steal (static_cast<S&&>(r));
  41                                                                                            assert (i == x); };
  42     #endif
  43
  44     byref (s); assert (i == 4);
  45     bycref (s); assert (i == 4);
  46     byval (s, 5); assert (i == 4);
  47     byrval (static_cast<S&&>(s), 6); assert (i == 5);
  48   }
  49   assert (i == 3);
  50 }
  51