libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <stack>
  10 // UNSUPPORTED: c++03, c++11, c++14
  11 // UNSUPPORTED: clang-5, apple-clang-9
  12 // UNSUPPORTED: libcpp-no-deduction-guides
  13 // Clang 5 will generate bad implicit deduction guides
  14 //      Specifically, for the copy constructor.
  15
  16
  17 // template<class Container>
  18 //   stack(Container) -> stack<typename Container::value_type, Container>;
  19 //
  20 // template<class Container, class Allocator>
  21 //   stack(Container, Allocator) -> stack<typename Container::value_type, Container>;
  22
  23
  24 #include <stack>
  25 #include <vector>
  26 #include <list>
  27 #include <iterator>
  28 #include <cassert>
  29 #include <cstddef>
  30 #include <climits> // INT_MAX
  31
  32 #include "test_macros.h"
  33 #include "test_iterators.h"
  34 #include "test_allocator.h"
  35
  36 struct A {};
  37
  38 int main(int, char**)
  39 {
  40
  41 //  Test the explicit deduction guides
  42     {
  43     std::vector<int> v{0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
  44     std::stack stk(v);
  45
  46     static_assert(std::is_same_v<decltype(stk), std::stack<int, std::vector<int>>>, "");
  47     assert(stk.size() == v.size());
  48     assert(stk.top() == v.back());
  49     }
  50
  51     {
  52     std::list<long, test_allocator<long>> l{10, 11, 12, 13, 14, 15, 16, 17, 18, 19 };
  53     std::stack stk(l, test_allocator<long>(0,2)); // different allocator
  54     static_assert(std::is_same_v<decltype(stk)::container_type, std::list<long, test_allocator<long>>>, "");
  55     static_assert(std::is_same_v<decltype(stk)::value_type, long>, "");
  56     assert(stk.size() == 10);
  57     assert(stk.top() == 19);
  58 //  I'd like to assert that we've gotten the right allocator in the stack, but
  59 //  I don't know how to get at the underlying container.
  60     }
  61
  62 //  Test the implicit deduction guides
  63
  64     {
  65 //  We don't expect this one to work - no way to implicitly get value_type
  66 //  std::stack stk(std::allocator<int>()); // stack (allocator &)
  67     }
  68
  69     {
  70     std::stack<A> source;
  71     std::stack stk(source); // stack(stack &)
  72     static_assert(std::is_same_v<decltype(stk)::value_type, A>, "");
  73     static_assert(std::is_same_v<decltype(stk)::container_type, std::deque<A>>, "");
  74     assert(stk.size() == 0);
  75     }
  76
  77     {
  78 //  This one is odd - you can pass an allocator in to use, but the allocator
  79 //  has to match the type of the one used by the underlying container
  80     typedef short T;
  81     typedef test_allocator<T> Alloc;
  82     typedef std::deque<T, Alloc> Container;
  83
  84     Container c{0,1,2,3};
  85     std::stack<T, Container> source(c);
  86     std::stack stk(source, Alloc(2)); // stack(stack &, allocator)
  87     static_assert(std::is_same_v<decltype(stk)::value_type, T>, "");
  88     static_assert(std::is_same_v<decltype(stk)::container_type, Container>, "");
  89     assert(stk.size() == 4);
  90     assert(stk.top() == 3);
  91     }
  92
  93
  94   return 0;
  95 }