src/base/orderedset.h

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2023  Vladimir Golovnev <glassez@yandex.ru>
   4  * Copyright (C) 2021  Mike Tzou (Chocobo1)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program 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  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  * In addition, as a special exception, the copyright holders give permission to
  21  * link this program with the OpenSSL project's "OpenSSL" library (or with
  22  * modified versions of it that use the same license as the "OpenSSL" library),
  23  * and distribute the linked executables. You must obey the GNU General Public
  24  * License in all respects for all of the code used other than "OpenSSL".  If you
  25  * modify file(s), you may extend this exception to your version of the file(s),
  26  * but you are not obligated to do so. If you do not wish to do so, delete this
  27  * exception statement from your version.
  28  */
  29
  30 #pragma once
  31
  32 #include <functional>
  33 #include <set>
  34 #include <type_traits>
  35
  36 #include "algorithm.h"
  37
  38 template <typename T, typename Compare = std::less<T>>
  39 class OrderedSet : public std::set<T, Compare>
  40 {
  41     using ThisType = OrderedSet<T, Compare>;
  42
  43 public:
  44     using BaseType = std::set<T, Compare>;
  45
  46     using key_type = typename BaseType::key_type;
  47     using value_type = typename BaseType::value_type;
  48
  49     using BaseType::BaseType;
  50     using BaseType::operator=;
  51
  52     // The following are custom functions that are in line with Qt API interface, such as `QSet`
  53
  54 #if __cplusplus < 202002L
  55     bool contains(const key_type &value) const
  56     {
  57         return (BaseType::find(value) != BaseType::cend());
  58     }
  59 #endif
  60
  61     int count() const
  62     {
  63         return static_cast<int>(BaseType::size());
  64     }
  65
  66     ThisType &intersect(const ThisType &other)
  67     {
  68         Algorithm::removeIf(*this, [&other](const value_type &value) -> bool
  69         {
  70             return !other.contains(value);
  71         });
  72         return *this;
  73     }
  74
  75     bool isEmpty() const
  76     {
  77         return BaseType::empty();
  78     }
  79
  80     template <typename std::enable_if_t<std::is_same_v<value_type, QString>, int> = 0>
  81     QString join(const QString &separator) const
  82     {
  83         auto iter = BaseType::cbegin();
  84         if (iter == BaseType::cend())
  85             return {};
  86
  87         QString ret = *iter;
  88         ++iter;
  89
  90         while (iter != BaseType::cend())
  91         {
  92             ret.push_back(separator + *iter);
  93             ++iter;
  94         }
  95
  96         return ret;
  97     }
  98
  99     bool remove(const key_type &value)
 100     {
 101         return (BaseType::erase(value) > 0);
 102     }
 103
 104     template <typename Set>
 105     ThisType &unite(const Set &other)
 106     {
 107         BaseType::insert(other.cbegin(), other.cend());
 108         return *this;
 109     }
 110
 111     template <typename Set>
 112     ThisType united(const Set &other) const
 113     {
 114         ThisType result = *this;
 115         result.unite(other);
 116         return result;
 117     }
 118 };