diff --git a/src/plugins/cppeditor/CMakeLists.txt b/src/plugins/cppeditor/CMakeLists.txt
index 90685aaf348..aef17fe4e31 100644
--- a/src/plugins/cppeditor/CMakeLists.txt
+++ b/src/plugins/cppeditor/CMakeLists.txt
@@ -127,6 +127,7 @@ add_qtc_plugin(CppEditor
     quickfixes/rewritecomment.cpp quickfixes/rewritecomment.cpp
     quickfixes/rewritecontrolstatements.cpp quickfixes/rewritecontrolstatements.h
     quickfixes/splitsimpledeclaration.cpp quickfixes/splitsimpledeclaration.h
+    quickfixes/synchronizememberfunctionorder.cpp quickfixes/synchronizememberfunctionorder.h
     resourcepreviewhoverhandler.cpp resourcepreviewhoverhandler.h
     searchsymbols.cpp searchsymbols.h
     semantichighlighter.cpp semantichighlighter.h
diff --git a/src/plugins/cppeditor/cppeditor.qbs b/src/plugins/cppeditor/cppeditor.qbs
index 24beed5dd18..c563c760971 100644
--- a/src/plugins/cppeditor/cppeditor.qbs
+++ b/src/plugins/cppeditor/cppeditor.qbs
@@ -283,6 +283,8 @@ QtcPlugin {
             "rewritecontrolstatements.h",
             "splitsimpledeclaration.cpp",
             "splitsimpledeclaration.h",
+            "synchronizememberfunctionorder.cpp",
+            "synchronizememberfunctionorder.h",
         ]
     }
 
diff --git a/src/plugins/cppeditor/cppeditor.qrc b/src/plugins/cppeditor/cppeditor.qrc
index e90b587dc2d..3a5ace117d3 100644
--- a/src/plugins/cppeditor/cppeditor.qrc
+++ b/src/plugins/cppeditor/cppeditor.qrc
@@ -41,5 +41,21 @@
         <file>testcases/move-class/template/theheader.h</file>
         <file>testcases/move-class/template/theheader.h_expected</file>
         <file>testcases/move-class/complex/theclass.h_expected</file>
+        <file>testcases/reorder-member-impls/different-locations/different-locations.pro</file>
+        <file>testcases/reorder-member-impls/different-locations/header.h</file>
+        <file>testcases/reorder-member-impls/different-locations/header.h_expected</file>
+        <file>testcases/reorder-member-impls/different-locations/impl1.cpp</file>
+        <file>testcases/reorder-member-impls/different-locations/impl1.cpp_expected</file>
+        <file>testcases/reorder-member-impls/different-locations/impl2.cpp</file>
+        <file>testcases/reorder-member-impls/different-locations/impl2.cpp_expected</file>
+        <file>testcases/reorder-member-impls/already-sorted/already-sorted.pro</file>
+        <file>testcases/reorder-member-impls/already-sorted/header.h</file>
+        <file>testcases/reorder-member-impls/no-out-of-line/header.h</file>
+        <file>testcases/reorder-member-impls/no-out-of-line/no-out-of-line.pro</file>
+        <file>testcases/reorder-member-impls/already-sorted/header.h_expected</file>
+        <file>testcases/reorder-member-impls/no-out-of-line/header.h_expected</file>
+        <file>testcases/reorder-member-impls/templates/header.h</file>
+        <file>testcases/reorder-member-impls/templates/header.h_expected</file>
+        <file>testcases/reorder-member-impls/templates/templates.pro</file>
     </qresource>
 </RCC>
diff --git a/src/plugins/cppeditor/quickfixes/cppquickfix.cpp b/src/plugins/cppeditor/quickfixes/cppquickfix.cpp
index 006008dd88c..a4052db83ec 100644
--- a/src/plugins/cppeditor/quickfixes/cppquickfix.cpp
+++ b/src/plugins/cppeditor/quickfixes/cppquickfix.cpp
@@ -33,6 +33,7 @@
 #include "rewritecomment.h"
 #include "rewritecontrolstatements.h"
 #include "splitsimpledeclaration.h"
+#include "synchronizememberfunctionorder.h"
 
 #include <extensionsystem/pluginmanager.h>
 #include <extensionsystem/pluginspec.h>
@@ -135,6 +136,7 @@ void createCppQuickFixFactories()
     registerRewriteCommentQuickfixes();
     registerRewriteControlStatementQuickfixes();
     registerSplitSimpleDeclarationQuickfix();
+    registerSynchronizeMemberFunctionOrderQuickfix();
 }
 
 static QList<CppQuickFixFactory *> g_cppQuickFixFactories;
diff --git a/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.cpp b/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.cpp
new file mode 100644
index 00000000000..400988bb659
--- /dev/null
+++ b/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.cpp
@@ -0,0 +1,358 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "synchronizememberfunctionorder.h"
+
+#include "../cppeditortr.h"
+#include "../cppeditorwidget.h"
+#include "../cpprefactoringchanges.h"
+#include "cppquickfix.h"
+#include "cppquickfixhelpers.h"
+
+#include <coreplugin/editormanager/editormanager.h>
+#include <cplusplus/ASTPath.h>
+
+#include <QList>
+#include <QHash>
+
+#ifdef WITH_TESTS
+#include "cppquickfix_test.h"
+#include <projectexplorer/kitmanager.h>
+#include <texteditor/textdocument.h>
+#include <QtTest>
+#endif
+
+#include <memory>
+
+using namespace Core;
+using namespace CPlusPlus;
+using namespace Utils;
+
+namespace CppEditor::Internal {
+namespace {
+
+class SynchronizeMemberFunctionOrderOp : public CppQuickFixOperation
+{
+public:
+    SynchronizeMemberFunctionOrderOp(
+        const CppQuickFixInterface &interface, const QList<Symbol *> &decls)
+        : CppQuickFixOperation(interface), m_state(std::make_shared<State>())
+    {
+        setDescription(
+            Tr::tr("Re-order Member Function Definitions According to Declaration Order"));
+        m_state->decls = decls;
+    }
+
+private:
+    struct DefLocation {
+        Symbol *decl = nullptr;
+        Link defLoc;
+        bool operator==(const DefLocation &other) const
+        {
+            return decl == other.decl && defLoc == other.defLoc;
+        }
+    };
+    using DefLocations = QList<DefLocation>;
+    struct State {
+        using Ptr = std::shared_ptr<State>;
+
+        void insertSorted(Symbol *decl, const Link &link) {
+            DefLocations &dl = defLocations[link.targetFilePath];
+            DefLocation newElem{decl, link};
+            const auto cmp = [](const DefLocation &elem, const DefLocation &value) {
+                if (elem.defLoc.targetLine < value.defLoc.targetLine)
+                    return true;
+                if (elem.defLoc.targetLine > value.defLoc.targetLine)
+                    return false;
+                return elem.defLoc.targetColumn < value.defLoc.targetColumn;
+            };
+            dl.insert(std::lower_bound(dl.begin(), dl.end(), newElem, cmp), newElem);
+        }
+
+        QList<Symbol *> decls;
+        QHash<FilePath, DefLocations> defLocations;
+        int remainingFollowSymbolOps = 0;
+    };
+
+    void perform() override
+    {
+        for (Symbol * const decl : std::as_const(m_state->decls)) {
+            QTextCursor cursor(currentFile()->document()->begin());
+            TranslationUnit * const tu = currentFile()->cppDocument()->translationUnit();
+            const int declPos = tu->getTokenPositionInDocument(decl->sourceLocation(),
+                                                               currentFile()->document());
+            cursor.setPosition(declPos);
+            const CursorInEditor cursorInEditor(
+                cursor,
+                decl->filePath(),
+                qobject_cast<CppEditorWidget *>(currentFile()->editor()),
+                currentFile()->editor()->textDocument(),
+                currentFile()->cppDocument());
+
+            const auto callback = [decl, declPos, doc = cursor.document(), state = m_state](
+                                      const Link &link) {
+                class FinishedChecker
+                {
+                public:
+                    FinishedChecker(const State::Ptr &state) : m_state(state)
+                    {}
+                    ~FinishedChecker()
+                    {
+                        if (--m_state->remainingFollowSymbolOps == 0)
+                            finish(m_state);
+                    };
+                private:
+                    const State::Ptr &m_state;
+                } finishedChecker(state);
+
+                if (!link.hasValidTarget())
+                    return;
+                if (decl->filePath() == link.targetFilePath) {
+                    const int linkPos = Text::positionInText(doc, link.targetLine,
+                                                             link.targetColumn + 1);
+                    if (linkPos == declPos)
+                        return;
+                }
+                state->insertSorted(decl, link);
+            };
+
+            ++m_state->remainingFollowSymbolOps;
+
+            // Force queued execution, as the built-in editor can run the callback synchronously.
+            const auto followSymbol = [cursorInEditor, callback] {
+                CppModelManager::followSymbol(
+                    cursorInEditor, callback, true, false, FollowSymbolMode::Exact);
+            };
+            QMetaObject::invokeMethod(CppModelManager::instance(), followSymbol, Qt::QueuedConnection);
+        }
+    }
+
+    // TODO: Move to some central place for re-use
+    static CppEditorWidget *getEditorWidget(const FilePath &filePath)
+    {
+        CppEditorWidget *editorWidget = nullptr;
+        const QList<IEditor *> editors = DocumentModel::editorsForFilePath(filePath);
+        for (IEditor *editor : editors) {
+            const auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor);
+            if (textEditor)
+                editorWidget = qobject_cast<CppEditorWidget *>(textEditor->editorWidget());
+            if (editorWidget)
+                return editorWidget;
+        }
+        return nullptr;
+    }
+
+    static void finish(const State::Ptr &state)
+    {
+        CppRefactoringChanges factory{CppModelManager::snapshot()};
+
+        // TODO: Move to some central place for re-use.
+        const auto createRefactoringFile = [&factory](const FilePath &filePath)
+        {
+            CppEditorWidget * const editorWidget = getEditorWidget(filePath);
+            return editorWidget ? factory.file(editorWidget, editorWidget->semanticInfo().doc)
+                                : factory.cppFile(filePath);
+        };
+
+        const auto findAstRange = [](const CppRefactoringFile &file, const Link &pos) {
+            const QList<AST *> astPath = ASTPath(
+                file.cppDocument())(pos.targetLine, pos.targetColumn + 1);
+            for (auto it = astPath.rbegin(); it != astPath.rend(); ++it) {
+                if (const auto funcDef = (*it)->asFunctionDefinition()) {
+                    AST *ast = funcDef;
+                    for (auto next = std::next(it);
+                         next != astPath.rend() && (*next)->asTemplateDeclaration();
+                         ++next) {
+                        ast = *next;
+                    }
+                    return file.range(ast);
+                }
+            }
+            return ChangeSet::Range();
+        };
+
+        for (auto it = state->defLocations.cbegin(); it != state->defLocations.cend(); ++it) {
+            const DefLocations &defLocsActualOrder = it.value();
+            const DefLocations defLocsExpectedOrder = Utils::sorted(
+                defLocsActualOrder, [](const DefLocation &loc1, const DefLocation &loc2) {
+                    return loc1.decl->sourceLocation() < loc2.decl->sourceLocation();
+                });
+            if (defLocsExpectedOrder == defLocsActualOrder)
+                continue;
+
+            CppRefactoringFilePtr file = createRefactoringFile(it.key());
+            ChangeSet changes;
+            for (int i = 0; i < defLocsActualOrder.size(); ++i) {
+                const DefLocation &actualLoc = defLocsActualOrder[i];
+                int expectedPos = -1;
+                for (int j = 0; j < defLocsExpectedOrder.size(); ++j) {
+                    if (defLocsExpectedOrder[j].decl == actualLoc.decl) {
+                        expectedPos = j;
+                        break;
+                    }
+                }
+                if (expectedPos == i)
+                    continue;
+                const ChangeSet::Range actualRange = findAstRange(*file, actualLoc.defLoc);
+                const ChangeSet::Range expectedRange
+                    = findAstRange(*file, defLocsActualOrder[expectedPos].defLoc);
+                if (actualRange.end > actualRange.start && expectedRange.end > expectedRange.start)
+                    changes.move(actualRange, expectedRange.start);
+            }
+            QTC_ASSERT(!changes.hadErrors(), continue);
+            file->setChangeSet(changes);
+            file->apply();
+        }
+    }
+
+    const State::Ptr m_state;
+};
+
+//! Ensures relative order of member function implementations is the same as declaration order.
+class SynchronizeMemberFunctionOrder : public CppQuickFixFactory
+{
+#ifdef WITH_TESTS
+public:
+    static QObject *createTest();
+#endif
+
+private:
+    void doMatch(const CppQuickFixInterface &interface, QuickFixOperations &result) override
+    {
+        ClassSpecifierAST * const classAst = astForClassOperations(interface);
+        if (!classAst || !classAst->symbol)
+            return;
+
+        QList<Symbol *> memberFunctions;
+        const TranslationUnit * const tu
+            = interface.currentFile()->cppDocument()->translationUnit();
+        for (int i = 0; i < classAst->symbol->memberCount(); ++i) {
+            Symbol *member = classAst->symbol->memberAt(i);
+
+            // Skip macros
+            if (tu->tokenAt(member->sourceLocation()).expanded())
+                continue;
+
+            if (const auto templ = member->asTemplate())
+                member = templ->declaration();
+            if (member->type()->asFunctionType() && !member->asFunction())
+                memberFunctions << member;
+        }
+        if (!memberFunctions.isEmpty())
+            result << new SynchronizeMemberFunctionOrderOp(interface, memberFunctions);
+    }
+};
+
+#ifdef WITH_TESTS
+using namespace Tests;
+
+class SynchronizeMemberFunctionOrderTest : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void test_data()
+    {
+        QTest::addColumn<QString>("projectName");
+        QTest::addColumn<bool>("expectChanges");
+
+        QTest::newRow("no out-of-line definitions") << "no-out-of-line" << false;
+        QTest::newRow("already sorted") << "already-sorted" << false;
+        QTest::newRow("different impl locations") << "different-locations" << true;
+        QTest::newRow("templates") << "templates" << true;
+    }
+
+    void test()
+    {
+        QFETCH(QString, projectName);
+        QFETCH(bool, expectChanges);
+        using namespace CppEditor::Tests;
+        using namespace ProjectExplorer;
+        using namespace TextEditor;
+
+        // Set up project.
+        Kit * const kit  = Utils::findOr(KitManager::kits(), nullptr, [](const Kit *k) {
+            return k->isValid() && !k->hasWarning() && k->value("QtSupport.QtInformation").isValid();
+        });
+        if (!kit)
+            QSKIP("The test requires at least one valid kit with a valid Qt");
+        const auto projectDir = std::make_unique<TemporaryCopiedDir>(
+            ":/cppeditor/testcases/reorder-member-impls/" + projectName);
+        SourceFilesRefreshGuard refreshGuard;
+        ProjectOpenerAndCloser projectMgr;
+        QVERIFY(projectMgr.open(projectDir->absolutePath(projectName + ".pro"), true, kit));
+        QVERIFY(refreshGuard.wait());
+
+        // Open header file and locate class.
+        const auto headerFilePath = projectDir->absolutePath("header.h");
+        QVERIFY2(headerFilePath.exists(), qPrintable(headerFilePath.toUserOutput()));
+        const auto editor = qobject_cast<BaseTextEditor *>(EditorManager::openEditor(headerFilePath));
+        QVERIFY(editor);
+        const auto doc = qobject_cast<TextEditor::TextDocument *>(editor->document());
+        QVERIFY(doc);
+        QTextCursor classCursor = doc->document()->find("struct S");
+        QVERIFY(!classCursor.isNull());
+        editor->setCursorPosition(classCursor.position());
+        const auto editorWidget = qobject_cast<CppEditorWidget *>(editor->editorWidget());
+        QVERIFY(editorWidget);
+        QVERIFY(TestCase::waitForRehighlightedSemanticDocument(editorWidget));
+
+        // Query factory.
+        SynchronizeMemberFunctionOrder factory;
+        CppQuickFixInterface quickFixInterface(editorWidget, ExplicitlyInvoked);
+        QuickFixOperations operations;
+        factory.match(quickFixInterface, operations);
+        operations.first()->perform();
+        if (expectChanges)
+            QVERIFY(waitForSignalOrTimeout(doc, &IDocument::saved, 30000));
+        QTest::qWait(1000);
+
+        // Compare all files.
+        const FileFilter filter({"*_expected"}, QDir::Files);
+        const FilePaths expectedDocuments = projectDir->filePath().dirEntries(filter);
+        QVERIFY(!expectedDocuments.isEmpty());
+        for (const FilePath &expected : expectedDocuments) {
+            static const QString suffix = "_expected";
+            const FilePath actual = expected.parentDir()
+                                        .pathAppended(expected.fileName().chopped(suffix.length()));
+            QVERIFY(actual.exists());
+            const auto actualContents = actual.fileContents();
+            QVERIFY(actualContents);
+            const auto expectedContents = expected.fileContents();
+            const QByteArrayList actualLines = actualContents->split('\n');
+            const QByteArrayList expectedLines = expectedContents->split('\n');
+            if (actualLines.size() != expectedLines.size()) {
+                qDebug().noquote().nospace() << "---\n" << *expectedContents << "EOF";
+                qDebug().noquote().nospace() << "+++\n" << *actualContents << "EOF";
+            }
+            QCOMPARE(actualLines.size(), expectedLines.size());
+            for (int i = 0; i < actualLines.size(); ++i) {
+                const QByteArray actualLine = actualLines.at(i);
+                const QByteArray expectedLine = expectedLines.at(i);
+                if (actualLine != expectedLine)
+                    qDebug() << "Unexpected content in line" << (i + 1) << "of file"
+                             << actual.fileName();
+                QCOMPARE(actualLine, expectedLine);
+            }
+        }
+    }
+};
+
+QObject *SynchronizeMemberFunctionOrder::createTest()
+{
+    return new SynchronizeMemberFunctionOrderTest;
+}
+
+#endif
+} // namespace
+
+void registerSynchronizeMemberFunctionOrderQuickfix()
+{
+    CppQuickFixFactory::registerFactory<SynchronizeMemberFunctionOrder>();
+}
+
+} // namespace CppEditor::Internal
+
+#ifdef WITH_TESTS
+#include <synchronizememberfunctionorder.moc>
+#endif
diff --git a/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.h b/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.h
new file mode 100644
index 00000000000..da6ad971dbb
--- /dev/null
+++ b/src/plugins/cppeditor/quickfixes/synchronizememberfunctionorder.h
@@ -0,0 +1,8 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+namespace CppEditor::Internal {
+void registerSynchronizeMemberFunctionOrderQuickfix();
+} // namespace CppEditor::Internal
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/already-sorted.pro b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/already-sorted.pro
new file mode 100644
index 00000000000..70518012691
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/already-sorted.pro
@@ -0,0 +1 @@
+HEADERS = header.h
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h
new file mode 100644
index 00000000000..c0d7e0caa77
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h
@@ -0,0 +1,9 @@
+struct S {
+    void firstFunction();
+    void secondFunction();
+    void thirdFunction();
+};
+
+void S::firstFunction() {}
+void S::secondFunction() {}
+void S::thirdFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h_expected
new file mode 100644
index 00000000000..c0d7e0caa77
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/already-sorted/header.h_expected
@@ -0,0 +1,9 @@
+struct S {
+    void firstFunction();
+    void secondFunction();
+    void thirdFunction();
+};
+
+void S::firstFunction() {}
+void S::secondFunction() {}
+void S::thirdFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/different-locations.pro b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/different-locations.pro
new file mode 100644
index 00000000000..a8dd832020e
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/different-locations.pro
@@ -0,0 +1,2 @@
+SOURCES = impl1.cpp impl2.cpp
+HEADERS = header.h
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h
new file mode 100644
index 00000000000..15a428eb7cb
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h
@@ -0,0 +1,15 @@
+struct S {
+    void firstFunction();
+    void secondFunction();
+    void thirdFunction() {}
+    void fourthFunction();
+    void fifthFunction();
+    void sixthFunction();
+    void seventhFunction();
+    void eighthFunction();
+    void ninthFunction();
+    void tenthFunction();
+};
+
+void S::tenthFunction() {}
+void S::fourthFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h_expected
new file mode 100644
index 00000000000..eeec93f300a
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/header.h_expected
@@ -0,0 +1,15 @@
+struct S {
+    void firstFunction();
+    void secondFunction();
+    void thirdFunction() {}
+    void fourthFunction();
+    void fifthFunction();
+    void sixthFunction();
+    void seventhFunction();
+    void eighthFunction();
+    void ninthFunction();
+    void tenthFunction();
+};
+
+void S::fourthFunction() {}
+void S::tenthFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp
new file mode 100644
index 00000000000..816fef17796
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp
@@ -0,0 +1,5 @@
+#include "header.h"
+
+void S::ninthFunction() {}
+void S::firstFunction() {}
+void S::secondFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp_expected
new file mode 100644
index 00000000000..24d0f3a212b
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl1.cpp_expected
@@ -0,0 +1,5 @@
+#include "header.h"
+
+void S::firstFunction() {}
+void S::secondFunction() {}
+void S::ninthFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp
new file mode 100644
index 00000000000..f1040e089ec
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp
@@ -0,0 +1,6 @@
+#include "header.h"
+
+void S::eighthFunction() {}
+void S::seventhFunction() {}
+void S::sixthFunction() {}
+void S::fifthFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp_expected
new file mode 100644
index 00000000000..2b65df96a5a
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/different-locations/impl2.cpp_expected
@@ -0,0 +1,6 @@
+#include "header.h"
+
+void S::fifthFunction() {}
+void S::sixthFunction() {}
+void S::seventhFunction() {}
+void S::eighthFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h
new file mode 100644
index 00000000000..cff89451279
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h
@@ -0,0 +1,5 @@
+struct S {
+    void firstFunction() {}
+    void secondFunction();
+    void thirdFunction() {}
+};
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h_expected
new file mode 100644
index 00000000000..cff89451279
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/header.h_expected
@@ -0,0 +1,5 @@
+struct S {
+    void firstFunction() {}
+    void secondFunction();
+    void thirdFunction() {}
+};
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/no-out-of-line.pro b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/no-out-of-line.pro
new file mode 100644
index 00000000000..70518012691
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/no-out-of-line/no-out-of-line.pro
@@ -0,0 +1 @@
+HEADERS = header.h
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h
new file mode 100644
index 00000000000..08b33a51d98
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h
@@ -0,0 +1,10 @@
+template <typename T> struct S {
+    void firstFunction();
+    template<typename U> void secondFunction(U);
+    template<typename U> void irrelevantFunction(U) {}
+    void thirdFunction();
+};
+
+template<typename T> template<typename U> void S<T>::secondFunction(U) {}
+template<typename T> void S<T>::thirdFunction() {}
+template<typename T> void S<T>::firstFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h_expected b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h_expected
new file mode 100644
index 00000000000..f182bbe62d4
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/header.h_expected
@@ -0,0 +1,10 @@
+template <typename T> struct S {
+    void firstFunction();
+    template<typename U> void secondFunction(U);
+    template<typename U> void irrelevantFunction(U) {}
+    void thirdFunction();
+};
+
+template<typename T> void S<T>::firstFunction() {}
+template<typename T> template<typename U> void S<T>::secondFunction(U) {}
+template<typename T> void S<T>::thirdFunction() {}
diff --git a/src/plugins/cppeditor/testcases/reorder-member-impls/templates/templates.pro b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/templates.pro
new file mode 100644
index 00000000000..70518012691
--- /dev/null
+++ b/src/plugins/cppeditor/testcases/reorder-member-impls/templates/templates.pro
@@ -0,0 +1 @@
+HEADERS = header.h