1// <experimental/functional> -*- C++ -*-
2
3// Copyright (C) 2014-2017 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 experimental/functional
26 *  This is a TS C++ Library header.
27 */
28
29#ifndef _GLIBCXX_EXPERIMENTAL_FUNCTIONAL
30#define _GLIBCXX_EXPERIMENTAL_FUNCTIONAL 1
31
32#pragma GCC system_header
33
34#if __cplusplus >= 201402L
35
36#include <functional>
37#include <tuple>
38#include <iterator>
39#include <unordered_map>
40#include <vector>
41#include <array>
42#include <bits/stl_algo.h>
43#ifdef _GLIBCXX_PARALLEL
44# include <parallel/algorithm> // For std::__parallel::search
45#endif
46#include <experimental/bits/lfts_config.h>
47
48namespace std _GLIBCXX_VISIBILITY(default)
49{
50namespace experimental
51{
52inline namespace fundamentals_v1
53{
54_GLIBCXX_BEGIN_NAMESPACE_VERSION
55
56  // See C++14 §20.9.9, Function object binders
57
58  /// Variable template for std::is_bind_expression
59  template<typename _Tp>
60    constexpr bool is_bind_expression_v = std::is_bind_expression<_Tp>::value;
61
62  /// Variable template for std::is_placeholder
63  template<typename _Tp>
64    constexpr int is_placeholder_v = std::is_placeholder<_Tp>::value;
65
66#define __cpp_lib_experimental_boyer_moore_searching 201411
67
68  // Searchers
69
70  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
71    class default_searcher
72    {
73    public:
74      default_searcher(_ForwardIterator1 __pat_first,
75		       _ForwardIterator1 __pat_last,
76		       _BinaryPredicate __pred = _BinaryPredicate())
77      : _M_m(__pat_first, __pat_last, std::move(__pred))
78      { }
79
80      template<typename _ForwardIterator2>
81	_ForwardIterator2
82	operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
83	{
84	  return std::search(__first, __last,
85			     std::get<0>(_M_m), std::get<1>(_M_m),
86			     std::get<2>(_M_m));
87	}
88
89    private:
90      std::tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
91    };
92
93  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
94    struct __boyer_moore_map_base
95    {
96      template<typename _RAIter>
97	__boyer_moore_map_base(_RAIter __pat, size_t __patlen,
98			       _Hash&& __hf, _Pred&& __pred)
99	: _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
100	{
101	  if (__patlen > 0)
102	    for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
103	      _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
104	}
105
106      using __diff_type = _Tp;
107
108      __diff_type
109      _M_lookup(_Key __key, __diff_type __not_found) const
110      {
111	auto __iter = _M_bad_char.find(__key);
112	if (__iter == _M_bad_char.end())
113	  return __not_found;
114	return __iter->second;
115      }
116
117      _Pred
118      _M_pred() const { return _M_bad_char.key_eq(); }
119
120      _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
121    };
122
123  template<typename _Tp, size_t _Len, typename _Pred>
124    struct __boyer_moore_array_base
125    {
126      template<typename _RAIter, typename _Unused>
127	__boyer_moore_array_base(_RAIter __pat, size_t __patlen,
128				 _Unused&&, _Pred&& __pred)
129	: _M_bad_char{ _GLIBCXX_STD_C::array<_Tp, _Len>{}, std::move(__pred) }
130	{
131	  std::get<0>(_M_bad_char).fill(__patlen);
132	  if (__patlen > 0)
133	    for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
134	      {
135		auto __ch = __pat[__i];
136		using _UCh = std::make_unsigned_t<decltype(__ch)>;
137		auto __uch = static_cast<_UCh>(__ch);
138		std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
139	      }
140	}
141
142      using __diff_type = _Tp;
143
144      template<typename _Key>
145	__diff_type
146	_M_lookup(_Key __key, __diff_type __not_found) const
147	{
148	  auto __ukey = static_cast<std::make_unsigned_t<_Key>>(__key);
149	  if (__ukey >= _Len)
150	    return __not_found;
151	  return std::get<0>(_M_bad_char)[__ukey];
152	}
153
154      const _Pred&
155      _M_pred() const { return std::get<1>(_M_bad_char); }
156
157      std::tuple<_GLIBCXX_STD_C::array<_Tp, _Len>, _Pred> _M_bad_char;
158    };
159
160  template<typename _Pred>
161    struct __is_std_equal_to : std::false_type { };
162
163  template<>
164    struct __is_std_equal_to<std::equal_to<void>> : std::true_type { };
165
166  // Use __boyer_moore_array_base when pattern consists of narrow characters
167  // and uses std::equal_to as the predicate.
168  template<typename _RAIter, typename _Hash, typename _Pred,
169           typename _Val = typename iterator_traits<_RAIter>::value_type,
170	   typename _Diff = typename iterator_traits<_RAIter>::difference_type>
171    using __boyer_moore_base_t
172      = std::conditional_t<sizeof(_Val) == 1 && is_integral<_Val>::value
173			   && __is_std_equal_to<_Pred>::value,
174			   __boyer_moore_array_base<_Diff, 256, _Pred>,
175			   __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
176
177  template<typename _RAIter, typename _Hash
178	     = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
179	   typename _BinaryPredicate = std::equal_to<>>
180    class boyer_moore_searcher
181    : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
182    {
183      using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
184      using typename _Base::__diff_type;
185
186    public:
187      boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
188			   _Hash __hf = _Hash(),
189			   _BinaryPredicate __pred = _BinaryPredicate());
190
191      template<typename _RandomAccessIterator2>
192	_RandomAccessIterator2
193	operator()(_RandomAccessIterator2 __first,
194		   _RandomAccessIterator2 __last) const;
195
196    private:
197      bool
198      _M_is_prefix(_RAIter __word, __diff_type __len,
199		   __diff_type __pos)
200      {
201	const auto& __pred = this->_M_pred();
202	__diff_type __suffixlen = __len - __pos;
203	for (__diff_type __i = 0; __i < __suffixlen; ++__i)
204	  if (!__pred(__word[__i], __word[__pos + __i]))
205	    return false;
206	return true;
207      }
208
209      __diff_type
210      _M_suffix_length(_RAIter __word, __diff_type __len,
211		       __diff_type __pos)
212      {
213	const auto& __pred = this->_M_pred();
214	__diff_type __i = 0;
215	while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
216	       && __i < __pos)
217	  {
218	    ++__i;
219	  }
220	return __i;
221      }
222
223      template<typename _Tp>
224	__diff_type
225	_M_bad_char_shift(_Tp __c) const
226	{ return this->_M_lookup(__c, _M_pat_end - _M_pat); }
227
228      _RAIter _M_pat;
229      _RAIter _M_pat_end;
230      _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
231    };
232
233  template<typename _RAIter, typename _Hash
234	     = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
235	   typename _BinaryPredicate = std::equal_to<>>
236    class boyer_moore_horspool_searcher
237    : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
238    {
239      using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
240      using typename _Base::__diff_type;
241
242    public:
243      boyer_moore_horspool_searcher(_RAIter __pat,
244				    _RAIter __pat_end,
245				    _Hash __hf = _Hash(),
246				    _BinaryPredicate __pred
247				    = _BinaryPredicate())
248      : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
249	_M_pat(__pat), _M_pat_end(__pat_end)
250      { }
251
252      template<typename _RandomAccessIterator2>
253	_RandomAccessIterator2
254	operator()(_RandomAccessIterator2 __first,
255		   _RandomAccessIterator2 __last) const
256	{
257	  const auto& __pred = this->_M_pred();
258	  auto __patlen = _M_pat_end - _M_pat;
259	  if (__patlen == 0)
260	    return __first;
261	  auto __len = __last - __first;
262	  while (__len >= __patlen)
263	    {
264	      for (auto __scan = __patlen - 1;
265		   __pred(__first[__scan], _M_pat[__scan]); --__scan)
266		if (__scan == 0)
267		  return __first;
268	      auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
269	      __len -= __shift;
270	      __first += __shift;
271	    }
272	  return __last;
273	}
274
275    private:
276      template<typename _Tp>
277	__diff_type
278	_M_bad_char_shift(_Tp __c) const
279	{ return this->_M_lookup(__c, _M_pat_end - _M_pat); }
280
281      _RAIter _M_pat;
282      _RAIter _M_pat_end;
283    };
284
285  /// Generator function for default_searcher
286  template<typename _ForwardIterator,
287	   typename _BinaryPredicate = std::equal_to<>>
288    inline default_searcher<_ForwardIterator, _BinaryPredicate>
289    make_default_searcher(_ForwardIterator __pat_first,
290			  _ForwardIterator __pat_last,
291			  _BinaryPredicate __pred = _BinaryPredicate())
292    { return { __pat_first, __pat_last, __pred }; }
293
294  /// Generator function for boyer_moore_searcher
295  template<typename _RAIter, typename _Hash
296	     = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
297	   typename _BinaryPredicate = equal_to<>>
298    inline boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>
299    make_boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
300			      _Hash __hf = _Hash(),
301			      _BinaryPredicate __pred = _BinaryPredicate())
302    { return { __pat_first, __pat_last, std::move(__hf), std::move(__pred) }; }
303
304  /// Generator function for boyer_moore_horspool_searcher
305  template<typename _RAIter, typename _Hash
306	     = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
307	   typename _BinaryPredicate = equal_to<>>
308    inline boyer_moore_horspool_searcher<_RAIter, _Hash, _BinaryPredicate>
309    make_boyer_moore_horspool_searcher(_RAIter __pat_first, _RAIter __pat_last,
310				       _Hash __hf = _Hash(),
311				       _BinaryPredicate __pred
312				       = _BinaryPredicate())
313    { return { __pat_first, __pat_last, std::move(__hf), std::move(__pred) }; }
314
315  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
316    boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
317    boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
318			 _Hash __hf, _BinaryPredicate __pred)
319    : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
320      _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
321    {
322      auto __patlen = __pat_end - __pat;
323      if (__patlen == 0)
324	return;
325      __diff_type __last_prefix = __patlen - 1;
326      for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
327	{
328	  if (_M_is_prefix(__pat, __patlen, __p + 1))
329	    __last_prefix = __p + 1;
330	  _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
331	}
332      for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
333	{
334	  auto __slen = _M_suffix_length(__pat, __patlen, __p);
335	  auto __pos = __patlen - 1 - __slen;
336	  if (!__pred(__pat[__p - __slen], __pat[__pos]))
337	    _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
338	}
339    }
340
341  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
342  template<typename _RandomAccessIterator2>
343    _RandomAccessIterator2
344    boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
345    operator()(_RandomAccessIterator2 __first,
346	       _RandomAccessIterator2 __last) const
347    {
348      auto __patlen = _M_pat_end - _M_pat;
349      if (__patlen == 0)
350	return __first;
351      const auto& __pred = this->_M_pred();
352      __diff_type __i = __patlen - 1;
353      auto __stringlen = __last - __first;
354      while (__i < __stringlen)
355	{
356	  __diff_type __j = __patlen - 1;
357	  while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
358	    {
359	      --__i;
360	      --__j;
361	    }
362	  if (__j < 0)
363	    return __first + __i + 1;
364	  __i += std::max(_M_bad_char_shift(__first[__i]),
365			  _M_good_suffix[__j]);
366	}
367      return __last;
368    }
369
370_GLIBCXX_END_NAMESPACE_VERSION
371} // namespace fundamentals_v1
372
373inline namespace fundamentals_v2
374{
375_GLIBCXX_BEGIN_NAMESPACE_VERSION
376
377#define __cpp_lib_experimental_not_fn 201406
378
379  /// [func.not_fn] Function template not_fn
380  template<typename _Fn>
381    inline auto
382    not_fn(_Fn&& __fn)
383    noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
384    {
385      return std::_Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
386    }
387
388_GLIBCXX_END_NAMESPACE_VERSION
389} // namespace fundamentals_v2
390} // namespace experimental
391} // namespace std
392
393#endif // C++14
394
395#endif // _GLIBCXX_EXPERIMENTAL_FUNCTIONAL
396