experimental/functional

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// <experimental/functional> -*- C++ -*-

// Copyright (C) 2014-2015 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 experimental/functional
 *  This is a TS C++ Library header.
 */

#ifndef _GLIBCXX_EXPERIMENTAL_FUNCTIONAL
#define _GLIBCXX_EXPERIMENTAL_FUNCTIONAL 1

#pragma GCC system_header

#if __cplusplus <= 201103L
# include <bits/c++14_warning.h>
#else

#include <functional>
#include <tuple>
#include <iterator>
#include <unordered_map>
#include <vector>
#include <array>
#include <bits/stl_algo.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
namespace experimental
{
inline namespace fundamentals_v1
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // See C++14 §20.9.9, Function object binders

  /// Variable template for std::is_bind_expression
  template<typename _Tp>
    constexpr bool is_bind_expression_v = std::is_bind_expression<_Tp>::value;

  /// Variable template for std::is_placeholder
  template<typename _Tp>
    constexpr int is_placeholder_v = std::is_placeholder<_Tp>::value;

#define __cpp_lib_experimental_boyer_moore_searching 201411

  // Searchers

  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
    class default_searcher
    {
    public:
      default_searcher(_ForwardIterator1 __pat_first,
                  _ForwardIterator1 __pat_last,
                  _BinaryPredicate __pred = _BinaryPredicate())
      : _M_m(__pat_first, __pat_last, std::move(__pred))
      { }

      template<typename _ForwardIterator2>
   _ForwardIterator2
   operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
   {
     return std::search(__first, __last,
                        std::get<0>(_M_m), std::get<1>(_M_m),
                        std::get<2>(_M_m));
   }

    private:
      std::tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
    };

  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
    struct __boyer_moore_map_base
    {
      template<typename _RAIter>
   __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
                          _Hash&& __hf, _Pred&& __pred)
   : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
   {
     if (__patlen > 0)
       for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
         _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
   }

      using __diff_type = _Tp;

      __diff_type
      _M_lookup(_Key __key, __diff_type __not_found) const
      {
   auto __iter = _M_bad_char.find(__key);
   if (__iter == _M_bad_char.end())
     return __not_found;
   return __iter->second;
      }

      _Pred
      _M_pred() const { return _M_bad_char.key_eq(); }

      std::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
    };

  template<typename _Tp, size_t _Len, typename _Pred>
    struct __boyer_moore_array_base
    {
      template<typename _RAIter, typename _Unused>
   __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
                            _Unused&&, _Pred&& __pred)
   : _M_bad_char{ {}, std::move(__pred) }
   {
     std::get<0>(_M_bad_char).fill(__patlen);
     if (__patlen > 0)
       for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
         {
           auto __ch = __pat[__i];
           using _UCh = std::make_unsigned_t<decltype(__ch)>;
           auto __uch = static_cast<_UCh>(__ch);
           std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
         }
   }

      using __diff_type = _Tp;

      template<typename _Key>
   __diff_type
   _M_lookup(_Key __key, __diff_type __not_found) const
   {
     auto __ukey = static_cast<std::make_unsigned_t<_Key>>(__key);
     if (__ukey >= _Len)
       return __not_found;
     return std::get<0>(_M_bad_char)[__ukey];
   }

      const _Pred&
      _M_pred() const { return std::get<1>(_M_bad_char); }

      std::tuple<std::array<_Tp, _Len>, _Pred> _M_bad_char;
    };

  template<typename _Pred>
    struct __is_std_equal_to : std::false_type { };

  template<>
    struct __is_std_equal_to<std::equal_to<void>> : std::true_type { };

  // Use __boyer_moore_array_base when pattern consists of narrow characters
  // and uses std::equal_to as the predicate.
  template<typename _RAIter, typename _Hash, typename _Pred,
           typename _Val = typename iterator_traits<_RAIter>::value_type,
      typename _Diff = typename iterator_traits<_RAIter>::difference_type>
    using __boyer_moore_base_t
      = std::conditional_t<sizeof(_Val) == 1 && is_integral<_Val>::value
                      && __is_std_equal_to<_Pred>::value,
                      __boyer_moore_array_base<_Diff, 256, _Pred>,
                      __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;

  template<typename _RAIter, typename _Hash
        = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
      typename _BinaryPredicate = std::equal_to<>>
    class boyer_moore_searcher
    : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
    {
      using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
      using typename _Base::__diff_type;

    public:
      boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
                      _Hash __hf = _Hash(),
                      _BinaryPredicate __pred = _BinaryPredicate());

      template<typename _RandomAccessIterator2>
   _RandomAccessIterator2
   operator()(_RandomAccessIterator2 __first,
              _RandomAccessIterator2 __last) const;

    private:
      bool
      _M_is_prefix(_RAIter __word, __diff_type __len,
              __diff_type __pos)
      {
   const auto& __pred = this->_M_pred();
   __diff_type __suffixlen = __len - __pos;
   for (__diff_type __i = 0; __i < __suffixlen; ++__i)
     if (!__pred(__word[__i], __word[__pos + __i]))
       return false;
   return true;
      }

      __diff_type
      _M_suffix_length(_RAIter __word, __diff_type __len,
                  __diff_type __pos)
      {
   const auto& __pred = this->_M_pred();
   __diff_type __i = 0;
   while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
          && __i < __pos)
     {
       ++__i;
     }
   return __i;
      }

      template<typename _Tp>
   __diff_type
   _M_bad_char_shift(_Tp __c) const
   { return this->_M_lookup(__c, _M_pat_end - _M_pat); }

      _RAIter _M_pat;
      _RAIter _M_pat_end;
      std::vector<__diff_type> _M_good_suffix;
    };

  template<typename _RAIter, typename _Hash
        = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
      typename _BinaryPredicate = std::equal_to<>>
    class boyer_moore_horspool_searcher
    : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
    {
      using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
      using typename _Base::__diff_type;

    public:
      boyer_moore_horspool_searcher(_RAIter __pat,
                               _RAIter __pat_end,
                               _Hash __hf = _Hash(),
                               _BinaryPredicate __pred
                               = _BinaryPredicate())
      : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
   _M_pat(__pat), _M_pat_end(__pat_end)
      { }

      template<typename _RandomAccessIterator2>
   _RandomAccessIterator2
   operator()(_RandomAccessIterator2 __first,
              _RandomAccessIterator2 __last) const
   {
     const auto& __pred = this->_M_pred();
     auto __patlen = _M_pat_end - _M_pat;
     if (__patlen == 0)
       return __first;
     auto __len = __last - __first;
     while (__len >= __patlen)
       {
         for (auto __scan = __patlen - 1;
              __pred(__first[__scan], _M_pat[__scan]); --__scan)
           if (__scan == 0)
             return __first;
         auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
         __len -= __shift;
         __first += __shift;
       }
     return __last;
   }

    private:
      template<typename _Tp>
   __diff_type
   _M_bad_char_shift(_Tp __c) const
   { return this->_M_lookup(__c, _M_pat_end - _M_pat); }

      _RAIter _M_pat;
      _RAIter _M_pat_end;
    };

  /// Generator function for default_searcher
  template<typename _ForwardIterator,
      typename _BinaryPredicate = std::equal_to<>>
    inline default_searcher<_ForwardIterator, _BinaryPredicate>
    make_default_searcher(_ForwardIterator __pat_first,
                     _ForwardIterator __pat_last,
                     _BinaryPredicate __pred = _BinaryPredicate())
    { return { __pat_first, __pat_last, __pred }; }

  /// Generator function for boyer_moore_searcher
  template<typename _RAIter, typename _Hash
        = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
      typename _BinaryPredicate = equal_to<>>
    inline boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>
    make_boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
                         _Hash __hf = _Hash(),
                         _BinaryPredicate __pred = _BinaryPredicate())
    { return { __pat_first, __pat_last, std::move(__hf), std::move(__pred) }; }

  /// Generator function for boyer_moore_horspool_searcher
  template<typename _RAIter, typename _Hash
        = std::hash<typename std::iterator_traits<_RAIter>::value_type>,
      typename _BinaryPredicate = equal_to<>>
    inline boyer_moore_horspool_searcher<_RAIter, _Hash, _BinaryPredicate>
    make_boyer_moore_horspool_searcher(_RAIter __pat_first, _RAIter __pat_last,
                                  _Hash __hf = _Hash(),
                                  _BinaryPredicate __pred
                                  = _BinaryPredicate())
    { return { __pat_first, __pat_last, std::move(__hf), std::move(__pred) }; }

  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
    boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
    boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
                    _Hash __hf, _BinaryPredicate __pred)
    : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
      _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
    {
      auto __patlen = __pat_end - __pat;
      if (__patlen == 0)
   return;
      __diff_type __last_prefix = __patlen - 1;
      for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
   {
     if (_M_is_prefix(__pat, __patlen, __p + 1))
       __last_prefix = __p + 1;
     _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
   }
      for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
   {
     auto __slen = _M_suffix_length(__pat, __patlen, __p);
     auto __pos = __patlen - 1 - __slen;
     if (!__pred(__pat[__p - __slen], __pat[__pos]))
       _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
   }
    }

  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
  template<typename _RandomAccessIterator2>
    _RandomAccessIterator2
    boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
    operator()(_RandomAccessIterator2 __first,
          _RandomAccessIterator2 __last) const
    {
      auto __patlen = _M_pat_end - _M_pat;
      if (__patlen == 0)
   return __first;
      const auto& __pred = this->_M_pred();
      __diff_type __i = __patlen - 1;
      auto __stringlen = __last - __first;
      while (__i < __stringlen)
   {
     __diff_type __j = __patlen - 1;
     while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
       {
         --__i;
         --__j;
       }
     if (__j < 0)
       return __first + __i + 1;
     __i += std::max(_M_bad_char_shift(__first[__i]),
                     _M_good_suffix[__j]);
   }
      return __last;
    }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace fundamentals_v1

inline namespace fundamentals_v2
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

#define __cpp_lib_experimental_not_fn 201406

  /// Generalized negator.
  template<typename _Fn>
    class _Not_fn
    {
      _Fn _M_fn;

    public:
      template<typename _Fn2>
   explicit
   _Not_fn(_Fn2&& __fn) : _M_fn(std::forward<_Fn2>(__fn)) { }

      _Not_fn(const _Not_fn& __fn) = default;
      _Not_fn(_Not_fn&& __fn) = default;
      _Not_fn& operator=(const _Not_fn& __fn) = default;
      _Not_fn& operator=(_Not_fn&& __fn) = default;
      ~_Not_fn() = default;

      template<typename... _Args>
   auto
   operator()(_Args&&... __args)
   noexcept(noexcept(!_M_fn(std::forward<_Args>(__args)...)))
   -> decltype(!_M_fn(std::forward<_Args>(__args)...))
   { return !_M_fn(std::forward<_Args>(__args)...); }

      template<typename... _Args>
   auto
   operator()(_Args&&... __args) const
   noexcept(noexcept(!_M_fn(std::forward<_Args>(__args)...)))
   -> decltype(!_M_fn(std::forward<_Args>(__args)...))
   { return !_M_fn(std::forward<_Args>(__args)...); }

      template<typename... _Args>
   auto
   operator()(_Args&&... __args) volatile
   noexcept(noexcept(!_M_fn(std::forward<_Args>(__args)...)))
   -> decltype(!_M_fn(std::forward<_Args>(__args)...))
   { return !_M_fn(std::forward<_Args>(__args)...); }

      template<typename... _Args>
   auto
   operator()(_Args&&... __args) const volatile
   noexcept(noexcept(!_M_fn(std::forward<_Args>(__args)...)))
   -> decltype(!_M_fn(std::forward<_Args>(__args)...))
   { return !_M_fn(std::forward<_Args>(__args)...); }
    };

  /// [func.not_fn] Function template not_fn
  template<typename _Fn>
    inline auto
    not_fn(_Fn&& __fn)
    noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
    {
      using __maybe_type = _Maybe_wrap_member_pointer<std::decay_t<_Fn>>;
      return _Not_fn<typename __maybe_type::type>{std::forward<_Fn>(__fn)};
    }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace fundamentals_v2
} // namespace experimental
} // namespace std

#endif // C++14

#endif // _GLIBCXX_EXPERIMENTAL_FUNCTIONAL