qBittorrent
algorithm.h
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1 /*
2  * Bittorrent Client using Qt and libtorrent.
3  * Copyright (C) 2018 Vladimir Golovnev <glassez@yandex.ru>
4  *
5  * This program is free software; you can redistribute it and/or
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27  */
28 
29 #pragma once
30 
31 #include <type_traits>
32 
33 namespace Algorithm
34 {
35  template <typename T, typename = void>
37  : std::false_type
38  {
39  };
40 
41  template <typename T>
42  struct HasMappedType<T, std::void_t<typename T::mapped_type>>
43  : std::true_type
44  {
45  };
46 
47  // To be used with associative array types, such as QMap, QHash and its variants
48  template <typename T, typename BinaryPredicate
49  , typename std::enable_if_t<HasMappedType<T>::value, int> = 0>
50  void removeIf(T &dict, BinaryPredicate &&p)
51  {
52  auto it = dict.begin();
53  while (it != dict.end())
54  it = (p(it.key(), it.value()) ? dict.erase(it) : ++it);
55  }
56 
57  // To be used with set types, such as QSet, std::set
58  template <typename T, typename UnaryPredicate
59  , typename std::enable_if_t<!HasMappedType<T>::value, int> = 0>
60  void removeIf(T &set, UnaryPredicate &&p)
61  {
62  auto it = set.begin();
63  while (it != set.end())
64  it = (p(*it) ? set.erase(it) : ++it);
65  }
66 }
void removeIf(T &dict, BinaryPredicate &&p)
Definition: algorithm.h:50
T value(const QString &key, const T &defaultValue={})
Definition: preferences.cpp:64