libstdc++-v3/testsuite/23_containers/vector/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 <vector>
  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::vector<unsigned> s0;
  39
  40   std::vector s1 = s0;
  41   check_type<std::vector<unsigned>>(s1);
  42
  43   std::vector s2 = std::move(s0);
  44   check_type<std::vector<unsigned>>(s2);
  45
  46   const std::vector s3 = s0;
  47   check_type<const std::vector<unsigned>>(s3);
  48
  49   const std::vector s4 = s3;
  50   check_type<const std::vector<unsigned>>(s4);
  51 }
  52
  53 void
  54 test01b()
  55 {
  56   std::vector<bool> s0;
  57
  58   std::vector s1 = s0;
  59   check_type<std::vector<bool>>(s1);
  60
  61   std::vector s2 = std::move(s0);
  62   check_type<std::vector<bool>>(s2);
  63
  64   const std::vector s3 = s0;
  65   check_type<const std::vector<bool>>(s3);
  66
  67   const std::vector s4 = s3;
  68   check_type<const std::vector<bool>>(s4);
  69 }
  70
  71 void
  72 test02()
  73 {
  74   unsigned a[1] = {};
  75   input_iterator_seq<unsigned> seq(a);
  76
  77   std::vector s1(seq.begin(), seq.end());
  78   check_type<std::vector<unsigned>>(s1);
  79
  80   std::vector s2(seq.begin(), seq.end(), std::allocator<unsigned>());
  81   check_type<std::vector<unsigned>>(s2);
  82
  83   std::vector s3(1U, 2L);
  84   check_type<std::vector<long>>(s3);
  85
  86   std::vector s4(1U, 2L, std::allocator<long>());
  87   check_type<std::vector<long>>(s4);
  88 }
  89
  90 void
  91 test02b()
  92 {
  93   bool a[1] = {};
  94   input_iterator_seq<bool> seq(a);
  95
  96   std::vector s1(seq.begin(), seq.end());
  97   check_type<std::vector<bool>>(s1);
  98
  99   std::vector s2(seq.begin(), seq.end(), std::allocator<bool>());
 100   check_type<std::vector<bool>>(s2);
 101
 102   std::vector s3(1U, true);
 103   check_type<std::vector<bool>>(s3);
 104
 105   std::vector s4(1U, true, std::allocator<bool>());
 106   check_type<std::vector<bool>>(s4);
 107 }
 108
 109 struct Pool;
 110
 111 template<typename T>
 112 struct Alloc : __gnu_test::SimpleAllocator<T>
 113 {
 114   Alloc(Pool*) { }
 115
 116   template<typename U>
 117     Alloc(const Alloc<U>&) { }
 118 };
 119
 120 void
 121 test_p1518r2()
 122 {
 123   // P1518R2 - Stop overconstraining allocators in container deduction guides.
 124   // This is a C++23 feature but we support it for C++17 too.
 125
 126   using Vector = std::vector<unsigned, Alloc<unsigned>>;
 127   Pool* p = nullptr;
 128   Vector v(p);
 129
 130   std::vector s1(v, p);
 131   check_type<Vector>(s1);
 132
 133   std::vector s2(std::move(v), p);
 134   check_type<Vector>(s2);
 135
 136   using BVector = std::vector<bool, Alloc<bool>>;
 137   BVector b(p);
 138
 139   std::vector s3(b, p);
 140   check_type<BVector>(s3);
 141
 142   std::vector s4(std::move(b), p);
 143   check_type<BVector>(s4);
 144 }