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Fix ambiguous call in {ranges, std}::find
1 parent 7532958 commit c4f700f

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6 files changed

+241
-35
lines changed

6 files changed

+241
-35
lines changed

‎libcxx/include/__algorithm/find.h

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -106,10 +106,10 @@ __find_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
106106
if (__first.__ctz_ != 0) {
107107
__storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
108108
__storage_type __dn = std::min(__clz_f, __n);
109-
__storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
109+
__storage_type __m = std::__middle_mask<__storage_type>(__first.__ctz_, __clz_f - __dn);
110110
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_) & __m;
111111
if (__b)
112-
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
112+
return _It(__first.__seg_, static_cast<unsigned>(std::__countr_zero(__b)));
113113
if (__n == __dn)
114114
return __first + __n;
115115
__n -= __dn;
@@ -119,14 +119,14 @@ __find_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
119119
for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) {
120120
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_);
121121
if (__b)
122-
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
122+
return _It(__first.__seg_, static_cast<unsigned>(std::__countr_zero(__b)));
123123
}
124124
// do last partial word
125125
if (__n > 0) {
126-
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
126+
__storage_type __m = std::__trailing_mask<__storage_type>(__bits_per_word - __n);
127127
__storage_type __b = std::__invert_if<!_ToFind>(*__first.__seg_) & __m;
128128
if (__b)
129-
return _It(__first.__seg_, static_cast<unsigned>(std::__libcpp_ctz(__b)));
129+
return _It(__first.__seg_, static_cast<unsigned>(std::__countr_zero(__b)));
130130
}
131131
return _It(__first.__seg_, static_cast<unsigned>(__n));
132132
}

‎libcxx/include/__bit/countr.h

Lines changed: 78 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -15,6 +15,8 @@
1515
#include <__bit/rotate.h>
1616
#include <__concepts/arithmetic.h>
1717
#include <__config>
18+
#include <__type_traits/enable_if.h>
19+
#include <__type_traits/is_unsigned.h>
1820
#include <limits>
1921

2022
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -38,20 +40,19 @@ _LIBCPP_BEGIN_NAMESPACE_STD
3840
return __builtin_ctzll(__x);
3941
}
4042

41-
template <class _Tp>
42-
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countr_zero(_Tp __t) _NOEXCEPT {
43-
#if __has_builtin(__builtin_ctzg)
44-
return __builtin_ctzg(__t, numeric_limits<_Tp>::digits);
45-
#else // __has_builtin(__builtin_ctzg)
46-
if (__t == 0)
47-
return numeric_limits<_Tp>::digits;
48-
if (sizeof(_Tp) <= sizeof(unsigned int))
43+
#if _LIBCPP_STD_VER >= 17
44+
// Implementation using constexpr if for C++ standards >= 17
45+
46+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero, which handles __t == 0 as a special case)
47+
template <class _Tp, __enable_if_t<is_unsigned<_Tp>::value, int> = 0>
48+
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 int __countr_zero_impl(_Tp __t) _NOEXCEPT {
49+
if constexpr (sizeof(_Tp) <= sizeof(unsigned int)) {
4950
return std::__libcpp_ctz(static_cast<unsigned int>(__t));
50-
else if (sizeof(_Tp) <= sizeof(unsigned long))
51+
} else if constexpr (sizeof(_Tp) <= sizeof(unsigned long)) {
5152
return std::__libcpp_ctz(static_cast<unsigned long>(__t));
52-
else if (sizeof(_Tp) <= sizeof(unsigned long long))
53+
} else if constexpr (sizeof(_Tp) <= sizeof(unsigned long long)) {
5354
return std::__libcpp_ctz(static_cast<unsigned long long>(__t));
54-
else {
55+
} else {
5556
int __ret = 0;
5657
const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
5758
while (static_cast<unsigned long long>(__t) == 0uLL) {
@@ -60,7 +61,72 @@ template <class _Tp>
6061
}
6162
return __ret + std::__libcpp_ctz(static_cast<unsigned long long>(__t));
6263
}
63-
#endif // __has_builtin(__builtin_ctzg)
64+
}
65+
66+
#else
67+
// Equivalent SFINAE-based implementation for older C++ standards < 17
68+
69+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero, which handles __t == 0 as a special case)
70+
template < class _Tp, __enable_if_t<is_unsigned<_Tp>::value && sizeof(_Tp) <= sizeof(unsigned int), int> = 0>
71+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero_impl(_Tp __t) _NOEXCEPT {
72+
return std::__libcpp_ctz(static_cast<unsigned int>(__t));
73+
}
74+
75+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero)
76+
template < class _Tp,
77+
__enable_if_t<is_unsigned<_Tp>::value && (sizeof(_Tp) > sizeof(unsigned int)) &&
78+
sizeof(_Tp) <= sizeof(unsigned long),
79+
int> = 0 >
80+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero_impl(_Tp __t) _NOEXCEPT {
81+
return std::__libcpp_ctz(static_cast<unsigned long>(__t));
82+
}
83+
84+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero)
85+
template < class _Tp,
86+
__enable_if_t<is_unsigned<_Tp>::value && (sizeof(_Tp) > sizeof(unsigned long)) &&
87+
sizeof(_Tp) <= sizeof(unsigned long long),
88+
int> = 0 >
89+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero_impl(_Tp __t) _NOEXCEPT {
90+
return std::__libcpp_ctz(static_cast<unsigned long long>(__t));
91+
}
92+
93+
# if _LIBCPP_STD_VER == 11
94+
95+
// Recursive constexpr implementation for C++11 due to limited constexpr support
96+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero)
97+
template < class _Tp, __enable_if_t<is_unsigned<_Tp>::value && (sizeof(_Tp) > sizeof(unsigned long long)), int> = 0 >
98+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero_impl(_Tp __t) _NOEXCEPT {
99+
unsigned long long __ull = static_cast<unsigned long long>(__t);
100+
const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
101+
return __ull == 0ull ? __ulldigits + std::__countr_zero_impl<_Tp>(__t >> __ulldigits) : std::__libcpp_ctz(__ull);
102+
}
103+
104+
# else
105+
106+
// Loop-based constexpr implementation for C++14 (and non-constexpr for C++03, 98)
107+
// Precondition: __t != 0 (This is guaranteed by the caller __countr_zero)
108+
template < class _Tp, __enable_if_t<is_unsigned<_Tp>::value && (sizeof(_Tp) > sizeof(unsigned long long)), int> = 0 >
109+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countr_zero_impl(_Tp __t) _NOEXCEPT {
110+
int __ret = 0;
111+
const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
112+
while (static_cast<unsigned long long>(__t) == 0uLL) {
113+
__ret += __ulldigits;
114+
__t >>= __ulldigits;
115+
}
116+
return __ret + std::__libcpp_ctz(static_cast<unsigned long long>(__t));
117+
}
118+
119+
# endif // _LIBCPP_STD_VER == 11
120+
121+
#endif // _LIBCPP_STD_VER >= 17
122+
123+
template <class _Tp>
124+
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero(_Tp __t) _NOEXCEPT {
125+
#if __has_builtin(__builtin_ctzg)
126+
return __builtin_ctzg(__t, numeric_limits<_Tp>::digits);
127+
#else
128+
return __t != 0 ? __countr_zero_impl(__t) : numeric_limits<_Tp>::digits;
129+
#endif
64130
}
65131

66132
#if _LIBCPP_STD_VER >= 20

‎libcxx/include/__fwd/bit_reference.h

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -10,6 +10,8 @@
1010
#define _LIBCPP___FWD_BIT_REFERENCE_H
1111

1212
#include <__config>
13+
#include <__type_traits/enable_if.h>
14+
#include <__type_traits/is_unsigned.h>
1315

1416
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1517
# pragma GCC system_header
@@ -20,6 +22,22 @@ _LIBCPP_BEGIN_NAMESPACE_STD
2022
template <class _Cp, bool _IsConst, typename _Cp::__storage_type = 0>
2123
class __bit_iterator;
2224

25+
template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
26+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __leading_mask(unsigned __shift) {
27+
return static_cast<_StorageType>(static_cast<_StorageType>(~static_cast<_StorageType>(0)) << __shift);
28+
}
29+
30+
template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
31+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __trailing_mask(unsigned __shift) {
32+
return static_cast<_StorageType>(static_cast<_StorageType>(~static_cast<_StorageType>(0)) >> __shift);
33+
}
34+
35+
template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
36+
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __middle_mask(unsigned __lshift, unsigned __rshift) {
37+
return static_cast<_StorageType>(
38+
std::__leading_mask<_StorageType>(__lshift) & std::__trailing_mask<_StorageType>(__rshift));
39+
}
40+
2341
_LIBCPP_END_NAMESPACE_STD
2442

2543
#endif // _LIBCPP___FWD_BIT_REFERENCE_H

‎libcxx/test/std/algorithms/alg.nonmodifying/alg.find/find.pass.cpp

Lines changed: 30 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -14,6 +14,7 @@
1414
// MSVC warning C4389: '==': signed/unsigned mismatch
1515
// MSVC warning C4805: '==': unsafe mix of type 'char' and type 'bool' in operation
1616
// ADDITIONAL_COMPILE_FLAGS(cl-style-warnings): /wd4245 /wd4305 /wd4310 /wd4389 /wd4805
17+
// XFAIL: FROZEN-CXX03-HEADERS-FIXME
1718

1819
// <algorithm>
1920

@@ -28,6 +29,7 @@
2829
#include <vector>
2930
#include <type_traits>
3031

32+
#include "sized_allocator.h"
3133
#include "test_macros.h"
3234
#include "test_iterators.h"
3335
#include "type_algorithms.h"
@@ -206,6 +208,33 @@ struct TestIntegerPromotions {
206208
}
207209
};
208210

211+
TEST_CONSTEXPR_CXX20 void test_bititer_with_custom_sized_types() {
212+
{
213+
using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
214+
std::vector<bool, Alloc> in(100, false, Alloc(1));
215+
in[in.size() - 2] = true;
216+
assert(std::find(in.begin(), in.end(), true) == in.end() - 2);
217+
}
218+
{
219+
using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
220+
std::vector<bool, Alloc> in(200, false, Alloc(1));
221+
in[in.size() - 2] = true;
222+
assert(std::find(in.begin(), in.end(), true) == in.end() - 2);
223+
}
224+
{
225+
using Alloc = sized_allocator<bool, std::uint32_t, std::int32_t>;
226+
std::vector<bool, Alloc> in(200, false, Alloc(1));
227+
in[in.size() - 2] = true;
228+
assert(std::find(in.begin(), in.end(), true) == in.end() - 2);
229+
}
230+
{
231+
using Alloc = sized_allocator<bool, std::uint64_t, std::int64_t>;
232+
std::vector<bool, Alloc> in(200, false, Alloc(1));
233+
in[in.size() - 2] = true;
234+
assert(std::find(in.begin(), in.end(), true) == in.end() - 2);
235+
}
236+
}
237+
209238
TEST_CONSTEXPR_CXX20 bool test() {
210239
types::for_each(types::integer_types(), TestTypes<char>());
211240
types::for_each(types::integer_types(), TestTypes<int>());
@@ -226,6 +255,7 @@ TEST_CONSTEXPR_CXX20 bool test() {
226255
#endif
227256

228257
types::for_each(types::integral_types(), TestIntegerPromotions());
258+
test_bititer_with_custom_sized_types();
229259

230260
return true;
231261
}

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