1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// test unsigned long to_ulong() const;
11
12#include <bitset>
13#include <algorithm>
14#include <type_traits>
15#include <limits>
16#include <climits>
17#include <cassert>
18
19template <std::size_t N>
20void test_to_ulong()
21{
22    const std::size_t M = sizeof(unsigned long) * CHAR_BIT < N ? sizeof(unsigned long) * CHAR_BIT : N;
23    const bool is_M_zero = std::integral_constant<bool, M == 0>::value; // avoid compiler warnings
24    const std::size_t X = is_M_zero ? sizeof(unsigned long) * CHAR_BIT - 1 : sizeof(unsigned long) * CHAR_BIT - M;
25    const std::size_t max = is_M_zero ? 0 : std::size_t(std::numeric_limits<unsigned long>::max()) >> X;
26    std::size_t tests[] = {0,
27                           std::min<std::size_t>(1, max),
28                           std::min<std::size_t>(2, max),
29                           std::min<std::size_t>(3, max),
30                           std::min(max, max-3),
31                           std::min(max, max-2),
32                           std::min(max, max-1),
33                           max};
34    for (std::size_t i = 0; i < sizeof(tests)/sizeof(tests[0]); ++i)
35    {
36        std::size_t j = tests[i];
37        std::bitset<N> v(j);
38        assert(j == v.to_ulong());
39    }
40
41    { // test values bigger than can fit into the bitset
42    const unsigned long val = 0x5AFFFFA5UL;
43    const bool canFit = N < sizeof(unsigned long) * CHAR_BIT;
44    const unsigned long mask = canFit ? (1UL << (canFit ? N : 0)) - 1 : (unsigned long)(-1); // avoid compiler warnings
45    std::bitset<N> v(val);
46    assert(v.to_ulong() == (val & mask)); // we shouldn't return bit patterns from outside the limits of the bitset.
47    }
48}
49
50int main()
51{
52    test_to_ulong<0>();
53    test_to_ulong<1>();
54    test_to_ulong<31>();
55    test_to_ulong<32>();
56    test_to_ulong<33>();
57    test_to_ulong<63>();
58    test_to_ulong<64>();
59    test_to_ulong<65>();
60    test_to_ulong<1000>();
61}
62