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

   1 // { dg-options "-std=gnu++17" }
   2 // { dg-do compile { target c++17 } }
   3
   4 #include <set>
   5 #include <testsuite_allocator.h>
   6
   7 using __gnu_test::SimpleAllocator;
   8
   9 static_assert(std::is_same_v<
  10               decltype(std::multiset{1, 2, 3}),
  11               std::multiset<int>>);
  12
  13 static_assert(std::is_same_v<
  14               decltype(std::multiset{1, 2, 3}),
  15               std::multiset<int>>);
  16
  17 static_assert(std::is_same_v<
  18               decltype(std::multiset{{1, 2, 3},
  19                     std::less<int>{}, {}}),
  20               std::multiset<int>>);
  21
  22 static_assert(std::is_same_v<
  23               decltype(std::multiset{{1, 2, 3},
  24                     {}}),
  25               std::multiset<int>>);
  26
  27 static_assert(std::is_same_v<
  28               decltype(std::multiset{{1, 2, 3},
  29                     {}, SimpleAllocator<int>{}}),
  30               std::multiset<int, std::less<int>,
  31               SimpleAllocator<int>>>);
  32
  33 void f()
  34 {
  35   std::multiset<int> x;
  36
  37   static_assert(std::is_same_v<
  38                 decltype(std::multiset(x.begin(), x.end())),
  39                 std::multiset<int>>);
  40
  41   static_assert(std::is_same_v<
  42                 decltype(std::multiset{x.begin(), x.end(),
  43                       std::less<int>{},
  44                       std::allocator<int>{}}),
  45                 std::multiset<int>>);
  46
  47   static_assert(std::is_same_v<
  48                 decltype(std::multiset{x.begin(), x.end(),
  49                       std::less<int>{}, {}}),
  50                 std::multiset<int>>);
  51
  52   static_assert(std::is_same_v<
  53                 decltype(std::multiset(x.begin(), x.end(),
  54                                   {})),
  55                 std::multiset<int>>);
  56
  57   static_assert(std::is_same_v<
  58                 decltype(std::multiset{x.begin(), x.end(),
  59                       {},
  60                       std::allocator<int>{}}),
  61                 std::multiset<int>>);
  62
  63   static_assert(std::is_same_v<
  64                 decltype(std::multiset{x.begin(), x.end(),
  65                       {},
  66                       SimpleAllocator<int>{}}),
  67                 std::multiset<int, std::less<int>, SimpleAllocator<int>>>);
  68 }