Add remove_if for maps

include/Utils.h

@@ -55,6 +55,19 @@ scaleDown(uint64_t max_width, uint64_t max_height, const ImageType &source)
           final_width, final_height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
 }
 
+//! Delete items in a container based on a predicate.
+template<typename ContainerT, typename PredicateT>
+void
+erase_if(ContainerT &items, const PredicateT &predicate)
+{
+        for (auto it = items.begin(); it != items.end();) {
+                if (predicate(*it))
+                        it = items.erase(it);
+                else
+                        ++it;
+        }
+};
+
 //! Calculate the Levenshtein distance between two strings with character skipping.
 int
 levenshtein_distance(const std::string &s1, const std::string &s2);

src/RoomList.cc

@@ -183,15 +183,12 @@ RoomList::initialize(const QMap<QString, RoomInfo> &info)
 void
 RoomList::cleanupInvites(const std::map<QString, bool> &invites)
 {
-        if (invites.empty())
+        if (invites.size() == 0)
                 return;
 
-        for (auto it = rooms_.begin(); it != rooms_.end();) {
-                if (it->second->isInvite() && (invites.find(it->first) == invites.end()))
-                        it = rooms_.erase(it);
-                else
-                        ++it;
-        }
+        utils::erase_if(rooms_, [invites](auto &room) {
+                return room.second->isInvite() && (invites.find(room.first) == invites.end());
+        });
 }
 
 void