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8d9254fc | 1 | // Copyright (C) 2019-2020 Free Software Foundation, Inc. |
281ab2fb JW |
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-options "-std=gnu++2a -D_GLIBCXX_ASSERTIONS" } | |
19 | // { dg-do run { target c++2a } } | |
20 | // { dg-xfail-run-if "__glibcxx_assert in ceil2 should fail" { *-*-* } } | |
21 | ||
22 | #include <bit> | |
23 | ||
24 | // P1355R2: not a constant expression if the result is not representable | |
25 | ||
26 | template<auto N, typename = void> | |
27 | struct ceil2_valid | |
28 | : std::false_type { }; | |
29 | ||
30 | template<auto N> | |
31 | struct ceil2_valid<N, std::void_t<char[(std::ceil2(N), 1)]>> | |
32 | : std::true_type { }; | |
33 | ||
34 | template<typename T> | |
35 | constexpr T max = std::numeric_limits<T>::max(); | |
36 | template<typename T> | |
37 | constexpr T maxpow2 = T(1) << (std::numeric_limits<T>::digits - 1); | |
38 | ||
39 | static_assert( ceil2_valid<maxpow2<unsigned char>>() ); | |
40 | static_assert( !ceil2_valid<maxpow2<unsigned char> + (unsigned char)1>() ); | |
41 | ||
42 | static_assert( !ceil2_valid<max<unsigned char>>() ); | |
43 | static_assert( !ceil2_valid<max<unsigned char> - (unsigned char)1>() ); | |
44 | ||
45 | static_assert( ceil2_valid<maxpow2<unsigned short>>() ); | |
46 | static_assert( !ceil2_valid<maxpow2<unsigned short> + (unsigned short)1>() ); | |
47 | static_assert( !ceil2_valid<max<unsigned short>>() ); | |
48 | static_assert( !ceil2_valid<max<unsigned short> - (unsigned short)1>() ); | |
49 | ||
50 | static_assert( ceil2_valid<maxpow2<unsigned int>>() ); | |
51 | static_assert( !ceil2_valid<maxpow2<unsigned int> + 1u>() ); | |
52 | static_assert( !ceil2_valid<max<unsigned int>>() ); | |
53 | static_assert( !ceil2_valid<max<unsigned int> - 1u>() ); | |
54 | ||
55 | static_assert( ceil2_valid<maxpow2<unsigned long>>() ); | |
56 | static_assert( !ceil2_valid<maxpow2<unsigned long> + 1ul>() ); | |
57 | static_assert( !ceil2_valid<max<unsigned long>>() ); | |
58 | static_assert( !ceil2_valid<max<unsigned long> - 1ul>() ); | |
59 | ||
60 | static_assert( ceil2_valid<maxpow2<unsigned long long>>() ); | |
61 | static_assert( !ceil2_valid<maxpow2<unsigned long long> + 1ull>() ); | |
62 | static_assert( !ceil2_valid<max<unsigned long long>>() ); | |
63 | static_assert( !ceil2_valid<max<unsigned long long> - 1ull>() ); | |
64 | ||
65 | void | |
66 | test01() | |
67 | { | |
68 | std::ceil2( maxpow2<unsigned> + 1u ); // should fail __glibcxx_assert | |
69 | } | |
70 | ||
71 | int main() | |
72 | { | |
73 | test01(); | |
74 | } |