Improve removeIf() to support set types

We can now replace QMutable*Iterator by removeIf() which usage is more consistent with other
algorithm functions.

src/base/algorithm.h

@@ -28,14 +28,42 @@
 
 #pragma once
 
-namespace Dict
+#include <type_traits>
+
+namespace Algorithm
 {
-    // To be used with QMap, QHash and it's variants
-    template <typename Dictionary, typename BinaryPredicate>
-    void removeIf(Dictionary &&dict, BinaryPredicate p)
+    template <typename ...>
+    using void_t = void;  // replace this with std::void_t in C++17
+
+    template <typename T, typename = void>
+    struct HasMappedType
+        : std::false_type
+    {
+    };
+
+    template <typename T>
+    struct HasMappedType<T, void_t<typename T::mapped_type>>
+        : std::true_type
+    {
+    };
+
+    // 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)
     {
         auto it = dict.begin();
         while (it != dict.end())
-            it = (p(it.key(), it.value()) ? dict.erase(it) : it + 1);
+            it = (p(it.key(), it.value()) ? dict.erase(it) : (it + 1));
+    }
+
+    // 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)
+    {
+        auto it = set.begin();
+        while (it != set.end())
+            it = (p(*it) ? set.erase(it) : (it + 1));
     }
 }