libstdc++-v3/testsuite/23_containers/queue/deduction.cc

   1 // Copyright (C) 2019-2025 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do compile { target c++17 } }
  19
  20 #include <queue>
  21 #include <deque>
  22 #include <list>
  23 #include <testsuite_allocator.h>
  24
  25 template<typename T, typename U> struct require_same;
  26 template<typename T> struct require_same<T, T> { using type = void; };
  27
  28 template<typename T, typename U>
  29   typename require_same<T, U>::type
  30   check_type(U&) { }
  31
  32 void
  33 test01()
  34 {
  35   std::queue<unsigned> s0;
  36
  37   std::queue s1 = s0;
  38   check_type<std::queue<unsigned>>(s1);
  39
  40   std::queue s2 = std::move(s0);
  41   check_type<std::queue<unsigned>>(s2);
  42
  43   const std::queue s3 = s0;
  44   check_type<const std::queue<unsigned>>(s3);
  45
  46   const std::queue s4 = s3;
  47   check_type<const std::queue<unsigned>>(s4);
  48
  49   std::allocator<unsigned> a;
  50   std::queue s5(s0, a);
  51   check_type<std::queue<unsigned>>(s5);
  52
  53   std::queue s6(std::move(s0), a);
  54   check_type<std::queue<unsigned>>(s6);
  55
  56   const std::queue s7(s3, a);
  57   check_type<const std::queue<unsigned>>(s7);
  58 }
  59
  60 void
  61 test02()
  62 {
  63   std::deque<unsigned> d;
  64   std::list<long> l;
  65
  66   std::queue s1(d);
  67   check_type<std::queue<unsigned>>(s1);
  68
  69   std::queue s2(d, d.get_allocator());
  70   check_type<std::queue<unsigned>>(s2);
  71
  72   std::queue s3(std::move(d));
  73   check_type<std::queue<unsigned>>(s3);
  74
  75   std::queue s4(std::move(d), d.get_allocator());
  76   check_type<std::queue<unsigned>>(s4);
  77
  78   std::queue s5(l);
  79   check_type<std::queue<long, std::list<long>>>(s5);
  80
  81   std::queue s6(l, l.get_allocator());
  82   check_type<std::queue<long, std::list<long>>>(s6);
  83
  84   std::queue s7(std::move(l));
  85   check_type<std::queue<long, std::list<long>>>(s7);
  86
  87   std::queue s8(std::move(l), l.get_allocator());
  88   check_type<std::queue<long, std::list<long>>>(s8);
  89 }
  90
  91 struct Pool;
  92
  93 template<typename T>
  94 struct Alloc : __gnu_test::SimpleAllocator<T>
  95 {
  96   Alloc(Pool*) { }
  97
  98   template<typename U>
  99     Alloc(const Alloc<U>&) { }
 100 };
 101
 102 void
 103 test_p1518r2()
 104 {
 105   // P1518R2 - Stop overconstraining allocators in container deduction guides.
 106   // This is a C++23 feature but we support it for C++17 too.
 107
 108   using Deque = std::deque<unsigned, Alloc<unsigned>>;
 109   using List = std::list<long, Alloc<long>>;
 110   Pool* p = nullptr;
 111   Deque d(p);
 112   List l(p);
 113
 114   std::queue q1(d, p);
 115   check_type<std::queue<unsigned, Deque>>(q1);
 116
 117   std::queue q2(l, p);
 118   check_type<std::queue<long, List>>(q2);
 119
 120   std::queue q3(q2, p);
 121   check_type<std::queue<long, List>>(q3);
 122 }