Use forwarding reference when passing function objects

So instead of passing every function objects by value (a copy is made), now function objects
will be handled properly by reference (for lvalues) or by value (for rvalues).

src/base/algorithm.h

@@ -50,7 +50,7 @@ namespace Algorithm
     // To be used with associative array types, such as QMap, QHash and it's variants
     template <typename T, typename BinaryPredicate
         , typename std::enable_if_t<HasMappedType<T>::value, int> = 0>
-    void removeIf(T &dict, BinaryPredicate p)
+    void removeIf(T &dict, BinaryPredicate &&p)
     {
         auto it = dict.begin();
         while (it != dict.end())
@@ -60,7 +60,7 @@ namespace Algorithm
     // To be used with set types, such as QSet, std::set
     template <typename T, typename UnaryPredicate
         , typename std::enable_if_t<!HasMappedType<T>::value, int> = 0>
-    void removeIf(T &set, UnaryPredicate p)
+    void removeIf(T &set, UnaryPredicate &&p)
     {
         auto it = set.begin();
         while (it != set.end())

src/base/settingvalue.h

@@ -50,7 +50,7 @@ public:
     // T proxyFunc(const T &a);
     template <typename ProxyFunc>
     explicit CachedSettingValue(const char *keyName, const T &defaultValue
-                                , ProxyFunc proxyFunc)
+                                , ProxyFunc &&proxyFunc)
         : m_keyName(QLatin1String(keyName))
         , m_value(proxyFunc(loadValue(defaultValue)))
     {