xref: /llvm-project/libcxx/test/std/containers/unord/unord.map/max_size.pass.cpp (revision fb855eb941b6d740cc6560297d0b4d3201dcaf9f)
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 // <unordered_map>
10 
11 // class unordered_map
12 
13 // size_type max_size() const;
14 
15 #include <cassert>
16 #include <limits>
17 #include <type_traits>
18 #include <unordered_map>
19 
20 #include "test_allocator.h"
21 #include "test_macros.h"
22 
main(int,char **)23 int main(int, char**)
24 {
25   typedef std::pair<const int, int> KV;
26   {
27     typedef limited_allocator<KV, 10> A;
28     typedef std::unordered_map<int, int, std::hash<int>, std::equal_to<int>, A>
29         C;
30     C c;
31     assert(c.max_size() <= 10);
32     LIBCPP_ASSERT(c.max_size() == 10);
33   }
34   {
35     typedef limited_allocator<KV, (std::size_t)-1> A;
36     typedef std::unordered_map<int, int, std::hash<int>, std::equal_to<int>, A>
37         C;
38     const C::size_type max_dist =
39         static_cast<C::size_type>(std::numeric_limits<C::difference_type>::max());
40     C c;
41     assert(c.max_size() <= max_dist);
42     LIBCPP_ASSERT(c.max_size() == max_dist);
43     }
44     {
45       typedef std::unordered_map<char, int> C;
46     const C::size_type max_dist =
47         static_cast<C::size_type>(std::numeric_limits<C::difference_type>::max());
48       C c;
49       assert(c.max_size() <= max_dist);
50       assert(c.max_size() <= alloc_max_size(c.get_allocator()));
51     }
52 
53   return 0;
54 }
55