libstdc++-v3/testsuite/20_util/uses_allocator/construction.cc

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2011-2021 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 20.6.7.2 uses-allocator construction
  21
  22 #include <memory>
  23 #include <tuple>
  24 #include <testsuite_hooks.h>
  25
  26 struct MyAlloc { };
  27
  28 // type that can't be constructed with an allocator
  29 struct CannotUse
  30 {
  31   CannotUse(int) : ok(true) { }
  32
  33   bool ok;
  34 };
  35
  36 // type that can be constructed with an allocator
  37 // but which has uses_allocator == false
  38 struct DoesNotUse
  39 {
  40   typedef MyAlloc allocator_type;
  41
  42   DoesNotUse(int) : ok(true) { }
  43   DoesNotUse(std::allocator_arg_t, MyAlloc, int) : ok(false) { }
  44   DoesNotUse(int, MyAlloc) : ok(false) { }
  45
  46   bool ok;
  47 };
  48
  49 namespace std
  50 {
  51   template<typename A>
  52     struct uses_allocator<DoesNotUse, A> : false_type { };
  53 }
  54
  55 // type that can be constructed with an allocator as second argument
  56 struct UsesWithTag
  57 {
  58   typedef MyAlloc allocator_type;
  59
  60   UsesWithTag(int) : ok(false) { }
  61   UsesWithTag(std::allocator_arg_t, MyAlloc, int) : ok(true) { }
  62   UsesWithTag(int, MyAlloc) : ok(false) {  }
  63
  64   bool ok;
  65 };
  66
  67 // type that can be constructed with an allocator as last argument
  68 struct UsesWithoutTag
  69 {
  70   typedef MyAlloc allocator_type;
  71
  72   UsesWithoutTag(int) : ok(false) { }
  73   UsesWithoutTag(int, MyAlloc) : ok(true) { }
  74
  75   bool ok;
  76 };
  77
  78
  79 template<typename TestType, typename... T>
  80   bool test2(T... args)
  81   {
  82     using std::allocator_arg;
  83     using std::tuple;
  84     using std::get;
  85
  86     tuple<TestType, T...> t(allocator_arg, MyAlloc(), 1, args...);
  87
  88     return get<0>(t).ok;
  89   }
  90
  91 template<typename... T>
  92   void test(T... args)
  93   {
  94     VERIFY( test2<CannotUse>(args...) );
  95     VERIFY( test2<DoesNotUse>(args...) );
  96     VERIFY( test2<UsesWithTag>(args...) );
  97     VERIFY( test2<UsesWithoutTag>(args...) );
  98   }
  99
 100 int main()
 101 {
 102   test();
 103   test(1);
 104   test(1, 2);
 105   return 0;
 106 }