[thirdparty/gcc.git] / libstdc++-v3 / include / std / bit

// <bit> -*- C++ -*-

// Copyright (C) 2018 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file include/bit
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_BIT
#define _GLIBCXX_BIT 1

#pragma GCC system_header

#if __cplusplus >= 201402L

#include <type_traits>
#include <limits>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  template<typename _Tp>
    constexpr _Tp
    __rotl(_Tp __x, unsigned int __s) noexcept
    {
      constexpr auto _Nd = numeric_limits<_Tp>::digits;
      const unsigned __sN = __s % _Nd;
      if (__sN)
        return (__x << __sN) | (__x >> (_Nd - __sN));
      return __x;
    }

  template<typename _Tp>
    constexpr _Tp
    __rotr(_Tp __x, unsigned int __s) noexcept
    {
      constexpr auto _Nd = numeric_limits<_Tp>::digits;
      const unsigned __sN = __s % _Nd;
      if (__sN)
        return (__x >> __sN) | (__x << (_Nd - __sN));
      return __x;
    }

  template<typename _Tp>
    constexpr int
    __countl_zero(_Tp __x) noexcept
    {
      using __limits = numeric_limits<_Tp>;

      if (__x == 0)
        return __limits::digits;

      using __limits_ull = numeric_limits<unsigned long long>;
      using __limits_ul = numeric_limits<unsigned long>;
      using __limits_u = numeric_limits<unsigned>;

      if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
	{
	  constexpr int __diff = __limits_u::digits - __limits::digits;
	  return __builtin_clz(__x) - __diff;
	}
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
	{
	  constexpr int __diff = __limits_ul::digits - __limits::digits;
	  return __builtin_clzl(__x) - __diff;
	}
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
	{
	  constexpr int __diff = __limits_ull::digits - __limits::digits;
	  return __builtin_clzll(__x) - __diff;
	}
      else // (__limits::digits > __limits_ull::digits)
	{
	  static_assert(__limits::digits <= (2 * __limits_ull::digits),
			"Maximum supported integer size is 128-bit");

	  unsigned long long __high = __x >> __limits_ull::digits;
	  if (__high != 0)
	    {
	      constexpr int __diff
		= (2 * __limits_ull::digits) - __limits::digits;
	      return __builtin_clzll(__high) - __diff;
	    }
	  unsigned long long __low = __x & __limits_ull::max();
	  return (__limits::digits - __limits_ull::digits)
	    + __builtin_clzll(__low);
	}
    }

  template<typename _Tp>
    constexpr int
    __countl_one(_Tp __x) noexcept
    {
      if (__x == numeric_limits<_Tp>::max())
        return numeric_limits<_Tp>::digits;
      return std::__countl_zero<_Tp>((_Tp)~__x);
    }

  template<typename _Tp>
    constexpr int
    __countr_zero(_Tp __x) noexcept
    {
      using __limits = numeric_limits<_Tp>;

      if (__x == 0)
        return __limits::digits;

      using __limits_ull = numeric_limits<unsigned long long>;
      using __limits_ul = numeric_limits<unsigned long>;
      using __limits_u = numeric_limits<unsigned>;

      if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
	return __builtin_ctz(__x);
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
	return __builtin_ctzl(__x);
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
	return __builtin_ctzll(__x);
      else // (__limits::digits > __limits_ull::digits)
	{
	  static_assert(__limits::digits <= (2 * __limits_ull::digits),
			"Maximum supported integer size is 128-bit");

	  unsigned long long __low = __x & __limits_ull::max();
	  if (__low != 0)
	    return __builtin_ctzll(__low);
	  unsigned long long __high = __x >> __limits_ull::digits;
	  return __builtin_ctzll(__high) + __limits_ull::digits;
	}
    }

  template<typename _Tp>
    constexpr int
    __countr_one(_Tp __x) noexcept
    {
      if (__x == numeric_limits<_Tp>::max())
        return numeric_limits<_Tp>::digits;
      return std::__countr_zero((_Tp)~__x);
    }

  template<typename _Tp>
    constexpr int
    __popcount(_Tp __x) noexcept
    {
      using __limits = numeric_limits<_Tp>;

      if (__x == 0)
        return 0;

      using __limits_ull = numeric_limits<unsigned long long>;
      using __limits_ul = numeric_limits<unsigned long>;
      using __limits_u = numeric_limits<unsigned>;

      if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
	return __builtin_popcount(__x);
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
	return __builtin_popcountl(__x);
      else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
	return __builtin_popcountll(__x);
      else // (__limits::digits > __limits_ull::digits)
	{
	  static_assert(__limits::digits <= (2 * __limits_ull::digits),
			"Maximum supported integer size is 128-bit");

	  unsigned long long __low = __x & __limits_ull::max();
	  unsigned long long __high = __x >> __limits_ull::digits;
	  return __builtin_popcountll(__low) + __builtin_popcountll(__high);
	}
    }

  template<typename _Tp>
    constexpr bool
    __ispow2(_Tp __x) noexcept
    { return std::__popcount(__x) == 1; }

  template<typename _Tp>
    constexpr _Tp
    __ceil2(_Tp __x) noexcept
    {
      constexpr auto _Nd = numeric_limits<_Tp>::digits;
      if (__x == 0)
        return 1;
      return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x - 1u)));
    }

  template<typename _Tp>
    constexpr _Tp
    __floor2(_Tp __x) noexcept
    {
      constexpr auto _Nd = numeric_limits<_Tp>::digits;
      if (__x == 0)
        return 0;
      return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x >> 1)));
    }

  template<typename _Tp>
    constexpr _Tp
    __log2p1(_Tp __x) noexcept
    {
      constexpr auto _Nd = numeric_limits<_Tp>::digits;
      if (__x == 0)
	return 0;
      return _Nd - std::__countl_zero(__x);
    }

#if __cplusplus > 201703L

  template<typename _Tp, typename _Up, bool = is_integral_v<_Tp>>
    struct _If_is_unsigned_integer_type { };

  template<typename _Up>
    struct _If_is_unsigned_integer_type<bool, _Up, true> { };

  template<typename _Tp, typename _Up>
    struct _If_is_unsigned_integer_type<_Tp, _Up, true>
    : enable_if<is_same_v<_Tp, make_unsigned_t<_Tp>>, _Up> { };

  template<typename _Tp, typename _Up = _Tp>
    using _If_is_unsigned_integer
      = typename _If_is_unsigned_integer_type<_Tp, _Up>::type;

#if ! __STRICT_ANSI__
  // [bitops.rot], rotating

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp>
    rotl(_Tp __x, unsigned int __s) noexcept
    { return std::__rotl(__x, __s); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp>
    rotr(_Tp __x, unsigned int __s) noexcept
    { return std::__rotr(__x, __s); }

  // [bitops.count], counting

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, int>
    countl_zero(_Tp __x) noexcept
    { return std::__countl_zero(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, int>
    countl_one(_Tp __x) noexcept
    { return std::__countl_one(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, int>
    countr_zero(_Tp __x) noexcept
    { return std::__countr_zero(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, int>
    countr_one(_Tp __x) noexcept
    { return std::__countr_one(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, int>
    popcount(_Tp __x) noexcept
    { return std::__popcount(__x); }
#endif

  // Integral power-of-two operations

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp, bool>
    ispow2(_Tp __x) noexcept
    { return std::__ispow2(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp>
    ceil2(_Tp __x) noexcept
    { return std::__ceil2(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp>
    floor2(_Tp __x) noexcept
    { return std::__floor2(__x); }

  template<typename _Tp>
    constexpr _If_is_unsigned_integer<_Tp>
    log2p1(_Tp __x) noexcept
    { return std::__log2p1(__x); }

#if ! __STRICT_ANSI__
  enum class byte : unsigned char;

  constexpr byte
  rotl(byte __x, unsigned int __s) noexcept
  { return (byte)std::__rotl((unsigned char)__x, __s); }

  constexpr byte
  rotr(byte __x, unsigned int __s) noexcept
  { return (byte)std::__rotr((unsigned char)__x, __s); }

  constexpr int
  countl_zero(byte __x) noexcept
  { return std::__countl_zero((unsigned char)__x); }

  constexpr int
  countl_one(byte __x) noexcept
  { return std::__countl_one((unsigned char)__x); }

  constexpr int
  countr_zero(byte __x) noexcept
  { return std::__countr_zero((unsigned char)__x); }

  constexpr int
  countr_one(byte __x) noexcept
  { return std::__countr_one((unsigned char)__x); }

  constexpr int
  popcount(byte __x) noexcept
  { return std::__popcount((unsigned char)__x); }

  constexpr bool
  ispow2(byte __x) noexcept
  { return std::__ispow2((unsigned char)__x); }

  constexpr byte
  ceil2(byte __x) noexcept
  { return (byte)std::__ceil2((unsigned char)__x); }

  constexpr byte
  floor2(byte __x) noexcept
  { return (byte)std::__floor2((unsigned char)__x); }

  constexpr byte
  log2p1(byte __x) noexcept
  { return (byte)std::__log2p1((unsigned char)__x); }
#endif

#endif // C++2a

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif // C++14
#endif // _GLIBCXX_BIT
Commit	Line	Data
f3e91052 JW	1	// <bit> -- C++ --
	2
	3	// Copyright (C) 2018 Free Software Foundation, Inc.
	4	//
	5	// This file is part of the GNU ISO C++ Library. This library is free
	6	// software; you can redistribute it and/or modify it under the
	7	// terms of the GNU General Public License as published by the
	8	// Free Software Foundation; either version 3, or (at your option)
	9	// any later version.
	10
	11	// This library is distributed in the hope that it will be useful,
	12	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	// GNU General Public License for more details.
	15
	16	// Under Section 7 of GPL version 3, you are granted additional
	17	// permissions described in the GCC Runtime Library Exception, version
	18	// 3.1, as published by the Free Software Foundation.
	19
	20	// You should have received a copy of the GNU General Public License and
	21	// a copy of the GCC Runtime Library Exception along with this program;
	22	// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
	23	// <http://www.gnu.org/licenses/>.
	24
	25	/** @file include/bit
	26	* This is a Standard C++ Library header.
	27	*/
	28
	29	#ifndef _GLIBCXX_BIT
	30	#define _GLIBCXX_BIT 1
	31
	32	#pragma GCC system_header
	33
	34	#if __cplusplus >= 201402L
	35
	36	#include <type_traits>
	37	#include <limits>
	38
	39	namespace std _GLIBCXX_VISIBILITY(default)
	40	{
	41	_GLIBCXX_BEGIN_NAMESPACE_VERSION
	42
	43	template<typename _Tp>
	44	constexpr _Tp
	45	__rotl(_Tp __x, unsigned int __s) noexcept
	46	{
	47	constexpr auto _Nd = numeric_limits<_Tp>::digits;
	48	const unsigned __sN = __s % _Nd;
	49	if (__sN)
	50	return (__x << __sN) \| (__x >> (_Nd - __sN));
	51	return __x;
	52	}
	53
	54	template<typename _Tp>
	55	constexpr _Tp
	56	__rotr(_Tp __x, unsigned int __s) noexcept
	57	{
	58	constexpr auto _Nd = numeric_limits<_Tp>::digits;
	59	const unsigned __sN = __s % _Nd;
	60	if (__sN)
	61	return (__x >> __sN) \| (__x << (_Nd - __sN));
	62	return __x;
	63	}
	64
65	template<typename _Tp>
66	constexpr int
67	__countl_zero(_Tp __x) noexcept
68	{
69	using __limits = numeric_limits<_Tp>;
70
71	if (__x == 0)
72	return __limits::digits;
73
74	using __limits_ull = numeric_limits<unsigned long long>;
75	using __limits_ul = numeric_limits<unsigned long>;
76	using __limits_u = numeric_limits<unsigned>;
77
78	if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
79	{
80	constexpr int __diff = __limits_u::digits - __limits::digits;
81	return __builtin_clz(__x) - __diff;
82	}
83	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
84	{
85	constexpr int __diff = __limits_ul::digits - __limits::digits;
86	return __builtin_clzl(__x) - __diff;
87	}
88	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
89	{
90	constexpr int __diff = __limits_ull::digits - __limits::digits;
91	return __builtin_clzll(__x) - __diff;
92	}
93	else // (__limits::digits > __limits_ull::digits)
94	{
95	static_assert(__limits::digits <= (2 * __limits_ull::digits),
96	"Maximum supported integer size is 128-bit");
97
98	unsigned long long __high = __x >> __limits_ull::digits;
99	if (__high != 0)
100	{
101	constexpr int __diff
102	= (2 * __limits_ull::digits) - __limits::digits;
103	return __builtin_clzll(__high) - __diff;
104	}
105	unsigned long long __low = __x & __limits_ull::max();
106	return (__limits::digits - __limits_ull::digits)
107	+ __builtin_clzll(__low);
108	}
109	}
110
111	template<typename _Tp>
112	constexpr int
113	__countl_one(_Tp __x) noexcept
114	{
115	if (__x == numeric_limits<_Tp>::max())
116	return numeric_limits<_Tp>::digits;
117	return std::__countl_zero<_Tp>((_Tp)~__x);
118	}
119
120	template<typename _Tp>
121	constexpr int
122	__countr_zero(_Tp __x) noexcept
123	{
124	using __limits = numeric_limits<_Tp>;
125
126	if (__x == 0)
127	return __limits::digits;
128
129	using __limits_ull = numeric_limits<unsigned long long>;
130	using __limits_ul = numeric_limits<unsigned long>;
131	using __limits_u = numeric_limits<unsigned>;
132
133	if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
134	return __builtin_ctz(__x);
135	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
136	return __builtin_ctzl(__x);
137	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
138	return __builtin_ctzll(__x);
139	else // (__limits::digits > __limits_ull::digits)
140	{
141	static_assert(__limits::digits <= (2 * __limits_ull::digits),
142	"Maximum supported integer size is 128-bit");
143
144	unsigned long long __low = __x & __limits_ull::max();
145	if (__low != 0)
146	return __builtin_ctzll(__low);
147	unsigned long long __high = __x >> __limits_ull::digits;
148	return __builtin_ctzll(__high) + __limits_ull::digits;
149	}
150	}
151
152	template<typename _Tp>
153	constexpr int
154	__countr_one(_Tp __x) noexcept
155	{
156	if (__x == numeric_limits<_Tp>::max())
157	return numeric_limits<_Tp>::digits;
158	return std::__countr_zero((_Tp)~__x);
159	}
160
161	template<typename _Tp>
162	constexpr int
163	__popcount(_Tp __x) noexcept
164	{
165	using __limits = numeric_limits<_Tp>;
166
167	if (__x == 0)
168	return 0;
169
170	using __limits_ull = numeric_limits<unsigned long long>;
171	using __limits_ul = numeric_limits<unsigned long>;
172	using __limits_u = numeric_limits<unsigned>;
173
174	if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_u::digits)
175	return __builtin_popcount(__x);
176	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ul::digits)
177	return __builtin_popcountl(__x);
178	else if _GLIBCXX17_CONSTEXPR (__limits::digits <= __limits_ull::digits)
179	return __builtin_popcountll(__x);
180	else // (__limits::digits > __limits_ull::digits)
181	{
182	static_assert(__limits::digits <= (2 * __limits_ull::digits),
183	"Maximum supported integer size is 128-bit");
184
185	unsigned long long __low = __x & __limits_ull::max();
186	unsigned long long __high = __x >> __limits_ull::digits;
187	return __builtin_popcountll(__low) + __builtin_popcountll(__high);
188	}
189	}
190
191	template<typename _Tp>
192	constexpr bool
193	__ispow2(_Tp __x) noexcept
194	{ return std::__popcount(__x) == 1; }
195
196	template<typename _Tp>
197	constexpr _Tp
198	__ceil2(_Tp __x) noexcept
199	{
200	constexpr auto _Nd = numeric_limits<_Tp>::digits;
201	if (__x == 0)
202	return 1;
203	return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x - 1u)));
204	}
205
206	template<typename _Tp>
207	constexpr _Tp
208	__floor2(_Tp __x) noexcept
209	{
210	constexpr auto _Nd = numeric_limits<_Tp>::digits;
211	if (__x == 0)
212	return 0;
213	return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x >> 1)));
214	}
215
216	template<typename _Tp>
217	constexpr _Tp
218	__log2p1(_Tp __x) noexcept
219	{
220	constexpr auto _Nd = numeric_limits<_Tp>::digits;
221	if (__x == 0)
222	return 0;
223	return _Nd - std::__countl_zero(__x);
224	}
225
226	#if __cplusplus > 201703L
227
228	template<typename _Tp, typename _Up, bool = is_integral_v<_Tp>>
229	struct _If_is_unsigned_integer_type { };
230
231	template<typename _Up>
232	struct _If_is_unsigned_integer_type<bool, _Up, true> { };
233
234	template<typename _Tp, typename _Up>
235	struct _If_is_unsigned_integer_type<_Tp, _Up, true>
236	: enable_if<is_same_v<_Tp, make_unsigned_t<_Tp>>, _Up> { };
237
238	template<typename _Tp, typename _Up = _Tp>
239	using _If_is_unsigned_integer
240	= typename _If_is_unsigned_integer_type<_Tp, _Up>::type;
241
242	#if ! __STRICT_ANSI__
243	// [bitops.rot], rotating
244
245	template<typename _Tp>
246	constexpr _If_is_unsigned_integer<_Tp>
247	rotl(_Tp __x, unsigned int __s) noexcept
248	{ return std::__rotl(__x, __s); }
249
250	template<typename _Tp>
251	constexpr _If_is_unsigned_integer<_Tp>
252	rotr(_Tp __x, unsigned int __s) noexcept
253	{ return std::__rotr(__x, __s); }
254
255	// [bitops.count], counting
256
257	template<typename _Tp>
258	constexpr _If_is_unsigned_integer<_Tp, int>
259	countl_zero(_Tp __x) noexcept
260	{ return std::__countl_zero(__x); }
261
262	template<typename _Tp>
263	constexpr _If_is_unsigned_integer<_Tp, int>
264	countl_one(_Tp __x) noexcept
265	{ return std::__countl_one(__x); }
266
267	template<typename _Tp>
268	constexpr _If_is_unsigned_integer<_Tp, int>
269	countr_zero(_Tp __x) noexcept
270	{ return std::__countr_zero(__x); }
271
272	template<typename _Tp>
273	constexpr _If_is_unsigned_integer<_Tp, int>
274	countr_one(_Tp __x) noexcept
275	{ return std::__countr_one(__x); }
276
277	template<typename _Tp>
278	constexpr _If_is_unsigned_integer<_Tp, int>
279	popcount(_Tp __x) noexcept
280	{ return std::__popcount(__x); }
281	#endif
282
283	// Integral power-of-two operations
284
285	template<typename _Tp>
286	constexpr _If_is_unsigned_integer<_Tp, bool>
287	ispow2(_Tp __x) noexcept
288	{ return std::__ispow2(__x); }
289
290	template<typename _Tp>
291	constexpr _If_is_unsigned_integer<_Tp>
292	ceil2(_Tp __x) noexcept
293	{ return std::__ceil2(__x); }
294
295	template<typename _Tp>
296	constexpr _If_is_unsigned_integer<_Tp>
297	floor2(_Tp __x) noexcept
298	{ return std::__floor2(__x); }
299
300	template<typename _Tp>
301	constexpr _If_is_unsigned_integer<_Tp>
302	log2p1(_Tp __x) noexcept
303	{ return std::__log2p1(__x); }
304
305	#if ! __STRICT_ANSI__
306	enum class byte : unsigned char;
307
308	constexpr byte
309	rotl(byte __x, unsigned int __s) noexcept
310	{ return (byte)std::__rotl((unsigned char)__x, __s); }
311
312	constexpr byte
313	rotr(byte __x, unsigned int __s) noexcept
314	{ return (byte)std::__rotr((unsigned char)__x, __s); }
315
316	constexpr int
317	countl_zero(byte __x) noexcept
318	{ return std::__countl_zero((unsigned char)__x); }
319
320	constexpr int
321	countl_one(byte __x) noexcept
322	{ return std::__countl_one((unsigned char)__x); }
323
324	constexpr int
325	countr_zero(byte __x) noexcept
326	{ return std::__countr_zero((unsigned char)__x); }
327
328	constexpr int
329	countr_one(byte __x) noexcept
330	{ return std::__countr_one((unsigned char)__x); }
331
332	constexpr int
333	popcount(byte __x) noexcept
334	{ return std::__popcount((unsigned char)__x); }
335
336	constexpr bool
337	ispow2(byte __x) noexcept
338	{ return std::__ispow2((unsigned char)__x); }
339
340	constexpr byte
341	ceil2(byte __x) noexcept
342	{ return (byte)std::__ceil2((unsigned char)__x); }
343
344	constexpr byte
345	floor2(byte __x) noexcept
346	{ return (byte)std::__floor2((unsigned char)__x); }
347
348	constexpr byte
349	log2p1(byte __x) noexcept
350	{ return (byte)std::__log2p1((unsigned char)__x); }
351	#endif
352
353	#endif // C++2a
354
355	_GLIBCXX_END_NAMESPACE_VERSION
356	} // namespace std
357
358	#endif // C++14
359	#endif // _GLIBCXX_BIT