libstdc++-v3/testsuite/23_containers/deque/cons/deduction.cc

   1 // Copyright (C) 2017-2025 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 <deque>
  21 #include <testsuite_iterators.h>
  22 #include <testsuite_allocator.h>
  23
  24 template<typename T>
  25   using input_iterator_seq
  26     = __gnu_test::test_container<T, __gnu_test::input_iterator_wrapper>;
  27
  28 template<typename T, typename U> struct require_same;
  29 template<typename T> struct require_same<T, T> { using type = void; };
  30
  31 template<typename T, typename U>
  32   typename require_same<T, U>::type
  33   check_type(U&) { }
  34
  35 void
  36 test01()
  37 {
  38   std::deque<unsigned> s0;
  39
  40   std::deque s1 = s0;
  41   check_type<std::deque<unsigned>>(s1);
  42
  43   std::deque s2 = std::move(s0);
  44   check_type<std::deque<unsigned>>(s2);
  45
  46   const std::deque s3 = s0;
  47   check_type<const std::deque<unsigned>>(s3);
  48
  49   const std::deque s4 = s3;
  50   check_type<const std::deque<unsigned>>(s4);
  51 }
  52
  53 void
  54 test02()
  55 {
  56   unsigned a[1] = {};
  57   input_iterator_seq<unsigned> seq(a);
  58
  59   std::deque s1(seq.begin(), seq.end());
  60   check_type<std::deque<unsigned>>(s1);
  61
  62   std::deque s2(seq.begin(), seq.end(), std::allocator<unsigned>());
  63   check_type<std::deque<unsigned>>(s2);
  64
  65   std::deque s3(1U, 2L);
  66   check_type<std::deque<long>>(s3);
  67
  68   std::deque s4(1U, 2L, std::allocator<long>());
  69   check_type<std::deque<long>>(s4);
  70 }
  71
  72 struct Pool;
  73
  74 template<typename T>
  75 struct Alloc : __gnu_test::SimpleAllocator<T>
  76 {
  77   Alloc(Pool*) { }
  78
  79   template<typename U>
  80     Alloc(const Alloc<U>&) { }
  81 };
  82
  83 void
  84 test_p1518r2()
  85 {
  86   // P1518R2 - Stop overconstraining allocators in container deduction guides.
  87   // This is a C++23 feature but we support it for C++17 too.
  88
  89   using Deque = std::deque<unsigned, Alloc<unsigned>>;
  90   Pool* p = nullptr;
  91   Deque d(p);
  92
  93   std::deque s1(d, p);
  94   check_type<Deque>(s1);
  95
  96   std::deque s2(std::move(d), p);
  97   check_type<Deque>(s2);
  98 }