gcc/testsuite/g++.dg/cpp1z/decomp3.C

   1 // { dg-do compile { target c++11 } }
   2 // { dg-options "" }
   3
   4 struct A { int a, b; float c; };
   5 A &bar ();
   6 struct B { int d; };
   7 B baz ();
   8
   9 void
  10 test (A &b, B c)
  11 {
  12   int && [ d ] = c;                     // { dg-error "structured binding declaration cannot have type 'int'" }
  13                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  14   char & [ e, f, ff ] { b };            // { dg-error "structured binding declaration cannot have type 'char'" }
  15                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  16   auto&[g,h,i]=b;                       // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } }
  17   decltype (auto) [ j ] = c;            // { dg-error "structured binding declaration cannot have type 'decltype.auto.'" "" { target c++14 } }
  18                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  19                                         // { dg-error "expected primary-expression before 'decltype'" "" { target c++11_down } .-2 }
  20   auto & & && & [ m, n, o ] = b;        // { dg-error "multiple ref-qualifiers" }
  21                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  22   constexpr auto [ p ] = c;             // { dg-error "structured binding declaration cannot be 'constexpr'" }
  23                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  24   friend auto [ q ] = c;                // { dg-error "'friend' used outside of class" }
  25                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  26   typedef auto [ r ] = c;               // { dg-error "structured binding declaration cannot be 'typedef'" }
  27                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  28   inline auto [ s ] = c;                // { dg-error "structured binding declaration cannot be 'inline'" }
  29                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  30   __restrict auto [ t ] = c;            // { dg-error "invalid use of 'restrict'" }
  31                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  32   long long auto [ u ] = c;             // { dg-error "'long long' specified with 'auto'" }
  33                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  34   virtual auto [ v ] = c;               // { dg-error "'virtual' outside class declaration" }
  35                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  36   explicit auto [ w ] = c;              // { dg-error "'explicit' outside class declaration" }
  37                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  38   static auto [ x ] = c;                // { dg-error "structured binding declaration cannot be 'static'" }
  39                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  40   extern auto [ y ] { c };              // { dg-error "structured binding declaration cannot be 'extern'" }
  41                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  42 }
  43
  44 void
  45 test2 (auto & [ p ] = bar ())           // { dg-error "'p' was not declared in this scope" }
  46 {                                       // { dg-warning "auto" "" { target { ! concepts } } .-1 }
  47 }
  48
  49 int arr[4];
  50
  51 void
  52 test3 (A &b, B c)
  53 {
  54   auto [ d, e, f ] = arr;               // { dg-error "only 3 names provided" }
  55                                         // { dg-message "while 'int .4.' decomposes into 4 elements" "" { target *-*-* } .-1 }
  56                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-2 }
  57   auto & [ g, h, i, j, k ] = arr;       // { dg-error "5 names provided" }
  58                                         // { dg-message "while 'int .4.' decomposes into 4 elements" "" { target *-*-* } .-1 }
  59                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-2 }
  60   auto [ l, m ] = b;                    // { dg-error "only 2 names provided" }
  61                                         // { dg-message "while 'A' decomposes into 3 elements" "" { target *-*-* } .-1 }
  62                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-2 }
  63   auto & [ n, o, p, q ] = b;            // { dg-error "4 names provided" }
  64                                         // { dg-message "while 'A' decomposes into 3 elements" "" { target *-*-* } .-1 }
  65                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-2 }
  66   auto [] { c };                        // { dg-error "empty structured binding declaration" }
  67                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-1 }
  68   auto [ r, s ] = c;                    // { dg-error "2 names provided" }
  69                                         // { dg-message "while 'B' decomposes into 1 element" "" { target *-*-* } .-1 }
  70                                         // { dg-warning "structured bindings only available with '-std=c..17' or '-std=gnu..17'" "" { target c++14_down } .-2 }
  71 }