diff --git a/src/plugins/cppeditor/cppcompletionassist.cpp b/src/plugins/cppeditor/cppcompletionassist.cpp
index 7a886a96c0f..4865f3dfedc 100644
--- a/src/plugins/cppeditor/cppcompletionassist.cpp
+++ b/src/plugins/cppeditor/cppcompletionassist.cpp
@@ -37,6 +37,8 @@
 #include <QTextDocument>
 #include <QIcon>
 
+#include <set>
+
 using namespace CPlusPlus;
 using namespace CppEditor;
 using namespace TextEditor;
@@ -847,27 +849,27 @@ bool InternalCppCompletionAssistProcessor::accepts() const
 IAssistProposal *InternalCppCompletionAssistProcessor::createContentProposal()
 {
     // Duplicates are kept only if they are snippets.
-    QSet<QString> processed;
-    auto it = m_completions.begin();
-    while (it != m_completions.end()) {
+    std::set<QString> processed;
+    for (auto it = m_completions.begin(); it != m_completions.end();) {
         if ((*it)->isSnippet()) {
             ++it;
-        } else if (!processed.contains((*it)->text())) {
-            auto item = static_cast<CppAssistProposalItem *>(*it);
-            processed.insert(item->text());
-            if (!item->isOverloaded()) {
-                if (auto symbol = qvariant_cast<Symbol *>(item->data())) {
-                    if (Function *funTy = symbol->type()->asFunctionType()) {
-                        if (funTy->hasArguments())
-                            item->markAsOverloaded();
-                    }
-                }
-            }
-            ++it;
-        } else {
+            continue;
+        }
+        if (!processed.insert((*it)->text()).second) {
             delete *it;
             it = m_completions.erase(it);
+            continue;
         }
+        auto item = static_cast<CppAssistProposalItem *>(*it);
+        if (!item->isOverloaded()) {
+            if (auto symbol = qvariant_cast<Symbol *>(item->data())) {
+                if (Function *funTy = symbol->type()->asFunctionType()) {
+                    if (funTy->hasArguments())
+                        item->markAsOverloaded();
+                }
+            }
+        }
+        ++it;
     }
 
     m_model->loadContent(m_completions);