[C++] SOme further g++.dg/cpp1z/decomp*.C tests

Hi!

This patch adds 3 new tests.  Tested on x86_64-linux, ok for trunk?

2016-11-15  Jakub Jelinek  <jakub@redhat.com>

	* g++.dg/cpp1z/decomp13.C: New test.
	* g++.dg/cpp1z/decomp14.C: New test.
	* g++.dg/cpp1z/decomp15.C: New test.


	Jakub

OK.

On Tue, Nov 15, 2016 at 9:13 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> This patch adds 3 new tests.  Tested on x86_64-linux, ok for trunk?
>
> 2016-11-15  Jakub Jelinek  <jakub@redhat.com>
>
>         * g++.dg/cpp1z/decomp13.C: New test.
>         * g++.dg/cpp1z/decomp14.C: New test.
>         * g++.dg/cpp1z/decomp15.C: New test.
>
> --- gcc/testsuite/g++.dg/cpp1z/decomp13.C.jj    2016-11-15 14:25:18.902048735 +0100
> +++ gcc/testsuite/g++.dg/cpp1z/decomp13.C       2016-11-15 14:48:12.795463351 +0100
> @@ -0,0 +1,30 @@
> +// { dg-do compile { target c++11 } }
> +// { dg-options "" }
> +
> +struct A { int f; };
> +struct B { int b; };
> +struct C : virtual A {};
> +struct D : virtual A {};
> +struct E { int f; };
> +struct F : A { int f; };
> +struct G : A, E {};
> +struct H : C, D {};
> +struct I : A, C {};            // { dg-warning "due to ambiguity" }
> +struct J : B {};
> +struct K : B, virtual J {};    // { dg-warning "due to ambiguity" }
> +struct L : virtual J {};
> +struct M : virtual J, L {};
> +
> +void
> +foo (C &c, F &f, G &g, H &h, I &i, K &k, M &m)
> +{
> +  auto [ ci ] = c;             // { dg-warning "decomposition declaration only available with" "" { target c++14_down } }
> +  auto [ fi ] = f;             // { dg-error "cannot decompose class type 'F': both it and its base class 'A' have non-static data members" }
> +                               // { dg-warning "decomposition declaration only available with" "" { target c++14_down } .-1 }
> +  auto [ gi ] = g;             // { dg-error "cannot decompose class type 'G': its base classes 'A' and 'E' have non-static data members" }
> +                               // { dg-warning "decomposition declaration only available with" "" { target c++14_down } .-1 }
> +  auto [ hi ] = h;             // { dg-warning "decomposition declaration only available with" "" { target c++14_down } }
> +  auto [ ki ] = k;             // { dg-error "'B' is an ambiguous base of 'K'" }
> +                               // { dg-warning "decomposition declaration only available with" "" { target c++14_down } .-1 }
> +  auto [ mi ] = m;             // { dg-warning "decomposition declaration only available with" "" { target c++14_down } }
> +}
> --- gcc/testsuite/g++.dg/cpp1z/decomp14.C.jj    2016-11-15 14:30:40.296941834 +0100
> +++ gcc/testsuite/g++.dg/cpp1z/decomp14.C       2016-11-15 14:50:32.361678491 +0100
> @@ -0,0 +1,24 @@
> +// { dg-do compile }
> +// { dg-options "-std=c++1z" }
> +
> +struct A { bool a, b; };
> +struct B { int a, b; };
> +
> +void
> +foo ()
> +{
> +  auto [ a, b ] = A ();
> +  for (auto [ a, b ] = A (); a; )
> +    ;
> +  if (auto [ a, b ] = A (); a)
> +    ;
> +  switch (auto [ a, b ] = B (); b)
> +    {
> +    case 2:
> +      break;
> +    }
> +  auto && [ c, d ] = A ();
> +  [[maybe_unused]] auto [ e, f ] = A ();
> +  alignas (A) auto [ g, h ] = A ();
> +  __attribute__((unused)) auto [ i, j ] = A ();
> +}
> --- gcc/testsuite/g++.dg/cpp1z/decomp15.C.jj    2016-11-15 14:38:55.198602649 +0100
> +++ gcc/testsuite/g++.dg/cpp1z/decomp15.C       2016-11-15 14:46:33.000000000 +0100
> @@ -0,0 +1,47 @@
> +// { dg-do compile }
> +// { dg-options "-std=c++1z" }
> +
> +struct A { bool a, b; };
> +struct B { int a, b; };
> +
> +void
> +foo ()
> +{
> +  auto [ a, b ] = A ();
> +  for (; auto [ a, b ] = A (); )                       // { dg-error "expected" }
> +    ;
> +  for (; false; auto [ a, b ] = A ())                  // { dg-error "expected" }
> +    ;
> +  if (auto [ a, b ] = A ())                            // { dg-error "expected" }
> +    ;
> +  if (auto [ a, b ] = A (); auto [ c, d ] = A ())      // { dg-error "expected" }
> +    ;
> +  if (int d = 5; auto [ a, b ] = A ())                 // { dg-error "expected" }
> +    ;
> +  switch (auto [ a, b ] = B ())                                // { dg-error "expected" }
> +    {
> +    case 2:
> +      break;
> +    }
> +  switch (int d = 5; auto [ a, b ] = B ())             // { dg-error "expected" }
> +    {
> +    case 2:
> +      break;
> +    }
> +  A e = A ();
> +  auto && [ c, d ] = e;
> +  auto [ i, j ] = A (), [ k, l ] = A ();               // { dg-error "expected" }
> +  auto m = A (), [ n, o ] = A ();                      // { dg-error "expected" }
> +}
> +
> +template <typename T>
> +auto [ a, b ] = A ();                                  // { dg-error "expected" }
> +
> +struct C
> +{
> +  auto [ e, f ] = A ();                                        // { dg-error "expected" }
> +  mutable auto [ g, h ] = A ();                                // { dg-error "expected" }
> +  virtual auto [ i, j ] = A ();                                // { dg-error "expected" }
> +  explicit auto [ k, l ] = A ();                       // { dg-error "expected" }
> +  friend auto [ m, n ] = A ();                         // { dg-error "expected" }
> +};
>
>         Jakub