libstdc++-v3/testsuite/ext/ext_pointer/1_neg.cc

   1 // Bob Walters 10-2008
   2
   3 // Test for Container using non-standard pointer types.
   4
   5 // Copyright (C) 2008, 2009, 2011
   6 // Free Software Foundation, Inc.
   7 //
   8 // This file is part of the GNU ISO C++ Library.  This library is free
   9 // software; you can redistribute it and/or modify it under the
  10 // terms of the GNU General Public License as published by the
  11 // Free Software Foundation; either version 3, or (at your option)
  12 // any later version.
  13
  14 // This library is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License along
  20 // with this library; see the file COPYING3.  If not see
  21 // <http://www.gnu.org/licenses/>.
  22
  23
  24 // { dg-do compile }
  25
  26 #include <algorithm>
  27 #include <testsuite_hooks.h>
  28 #include <ext/pointer.h>
  29
  30 using __gnu_cxx::_Pointer_adapter;
  31 using __gnu_cxx::_Relative_pointer_impl;
  32 using __gnu_cxx::__static_pointer_cast;
  33 using __gnu_cxx::__const_pointer_cast;
  34
  35
  36 struct A {
  37   int i;
  38 };
  39 struct B : public A{
  40   int j;
  41 };
  42 typedef _Pointer_adapter<_Relative_pointer_impl<B> > B_pointer;
  43 typedef _Pointer_adapter<_Relative_pointer_impl<const B> > const_B_pointer;
  44 typedef _Pointer_adapter<_Relative_pointer_impl<A> > A_pointer;
  45 typedef _Pointer_adapter<_Relative_pointer_impl<const A> > const_A_pointer;
  46
  47
  48 void test01(void) {
  49   bool test __attribute__((unused)) = true;
  50
  51   A a;
  52   B b;
  53
  54   A_pointer aptr( &a );
  55
  56   // Can't implicitly cast from A* to B*
  57   B_pointer bptr1(aptr); // { dg-error "required from here" 31 }
  58   B_pointer bptr2(&a); // { dg-error "required from here" 32 }
  59
  60   // but explicit cast/conversion is OK.
  61   B_pointer bptr3(__static_pointer_cast<B_pointer>(aptr)); // ok
  62   B_pointer bptr4(__static_pointer_cast<B_pointer>(&a)); // ok
  63
  64   // Can't implicitly cast from A* to B*
  65   bptr1 = aptr; // { dg-error "required from here" 39 }
  66   bptr1 = &a; // { dg-error "required from here" 40 }
  67
  68   // but explicit cast/conversion is OK.
  69   bptr1 = __static_pointer_cast<B_pointer>(aptr); // ok
  70   bptr1 = __static_pointer_cast<B_pointer>(&a); // ok
  71
  72   // Similarly, can't shed constness via implicit cast
  73   const_A_pointer captr(&a);
  74   A_pointer aptr2(captr); // { dg-error "required from here" 48 }
  75
  76   // but explicit cast/conversion is OK.
  77   A_pointer aptr3(__const_pointer_cast<A_pointer>(captr)); // ok
  78
  79   // Similarly, can't shed constness via implicit cast
  80   aptr2 = captr; // { dg-error "required from here" 54 }
  81
  82   // but explicit cast/conversion is OK.
  83   aptr3 = __const_pointer_cast<A_pointer>(captr); // ok
  84
  85   // Combine explicit const cast with implicit downcast.
  86   const_B_pointer cbptr(&b);
  87   A_pointer aptr4(cbptr); // { dg-error "required from here" 61 }
  88   aptr4 = cbptr; // { dg-error "required from here" 62 }
  89
  90   A_pointer aptr5(__const_pointer_cast<B_pointer>(cbptr)); // ok
  91   aptr5 = __const_pointer_cast<B_pointer>(cbptr);  // ok
  92 }
  93
  94 // { dg-prune-output "include" }