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99dee823 | 1 | // Copyright (C) 2018-2021 Free Software Foundation, Inc. |
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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 | ||
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18 | // { dg-options "-std=gnu++2a" } |
19 | // { dg-do compile { target c++2a } } | |
20 | ||
21 | #include <bit> | |
c03b53da | 22 | #include <limits> |
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23 | |
24 | template<typename UInt> | |
25 | constexpr auto | |
26 | test(UInt x) | |
27 | -> decltype(std::countl_one(x)) | |
28 | { | |
29 | static_assert( noexcept(std::countl_one(x)) ); | |
30 | ||
31 | constexpr unsigned digits = std::numeric_limits<UInt>::digits; | |
32 | ||
33 | static_assert( std::countl_one((UInt)0) == 0 ); | |
34 | static_assert( std::countl_one((UInt)-1) == digits ); | |
35 | ||
36 | static_assert( std::countl_one((UInt)3) == 0 ); | |
37 | static_assert( std::countl_one((UInt)((UInt)1 << digits - 1)) == 1 ); | |
38 | static_assert( std::countl_one((UInt)((UInt)3 << digits - 2)) == 2 ); | |
39 | static_assert( std::countl_one((UInt)((UInt)7 << digits - 3)) == 3 ); | |
40 | static_assert( std::countl_one((UInt)((UInt)255 << digits - 8)) == 8 ); | |
41 | ||
42 | if constexpr (std::numeric_limits<UInt>::digits > 8) | |
43 | { | |
44 | static_assert( std::countl_one((UInt)((UInt)-1 ^ 0x100)) == digits - 9 ); | |
45 | static_assert( std::countl_one((UInt)((UInt)-1 ^ 0x101)) == digits - 9 ); | |
46 | static_assert( std::countl_one((UInt)((UInt)-1 ^ 0x201)) == digits - 10 ); | |
47 | } | |
48 | ||
49 | if constexpr (std::numeric_limits<UInt>::digits > 64) | |
50 | { | |
51 | static_assert( std::countl_one((UInt)-1 ^ ((UInt)1 << 70)) == digits - 71 ); | |
52 | } | |
53 | ||
54 | return true; | |
55 | } | |
56 | ||
57 | static_assert( test( (unsigned char)0 ) ); | |
58 | static_assert( test( (unsigned short)0 ) ); | |
59 | static_assert( test( (unsigned int)0 ) ); | |
60 | static_assert( test( (unsigned long)0 ) ); | |
61 | static_assert( test( (unsigned long long)0 ) ); | |
62 | ||
63 | // std::countl_one(T) shall not participate in overload resolution | |
64 | // unless T is an unsigned integer type. | |
65 | struct X { constexpr bool did_not_match() { return true; } }; | |
66 | constexpr X test(...) { return X{}; } | |
67 | static_assert( test( (bool)0 ).did_not_match() ); | |
68 | static_assert( test( (char)0 ).did_not_match() ); | |
69 | static_assert( test( (int)0 ).did_not_match() ); | |
70 | static_assert( test( (char16_t)0 ).did_not_match() ); | |
71 | static_assert( test( (float)0 ).did_not_match() ); | |
72 | static_assert( test( (void*)0 ).did_not_match() ); | |
73 | static_assert( test( X{} ).did_not_match() ); | |
74 | enum E : unsigned { e }; | |
75 | static_assert( test( e ).did_not_match() ); | |
76 | ||
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77 | #if !defined(__STRICT_ANSI__) && defined _GLIBCXX_USE_INT128 |
78 | static_assert( test( (unsigned __int128)0 ) ); | |
79 | static_assert( test( (__int128)0 ).did_not_match() ); | |
80 | #endif | |
81 | #if defined(__GLIBCXX_TYPE_INT_N_0) | |
82 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_0)0 ) ); | |
83 | static_assert( test( (__GLIBCXX_TYPE_INT_N_0)0 ).did_not_match() ); | |
84 | #endif | |
85 | #if defined(__GLIBCXX_TYPE_INT_N_1) | |
86 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_1)0 ) ); | |
87 | static_assert( test( (__GLIBCXX_TYPE_INT_N_1)0 ).did_not_match() ); | |
88 | #endif | |
89 | #if defined(__GLIBCXX_TYPE_INT_N_2) | |
90 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_2)0 ) ); | |
91 | static_assert( test( (__GLIBCXX_TYPE_INT_N_2)0 ).did_not_match() ); | |
92 | #endif | |
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93 | |
94 | #include <cstddef> | |
95 | static_assert( test( (std::byte)0 ).did_not_match() ); |