QGeometryFactory: don't make op== virtual

That's too clever, and it backfires with compilation errors in C++20
mode:

  qt3d/tests/auto/render/meshfunctors/tst_meshfunctors.cpp:129:29: error: ambiguous overload for ‘operator==’ (operand types are ‘MeshFunctorA’ and ‘MeshFunctorB’)
    129 |         QVERIFY(!(*functorA == *functorB));
        |                   ~~~~~~~~~ ^~ ~~~~~~~~~
        |                   |            |
        |                   MeshFunctorA MeshFunctorB
  qt3d/tests/auto/render/meshfunctors/tst_meshfunctors.cpp:72:10: note: candidate: ‘virtual bool MeshFunctorB::operator==(const Qt3DCore::QGeometryFactory&) const’ (reversed)
     72 |     bool operator ==(const Qt3DCore::QGeometryFactory &other) const override
        |          ^~~~~~~~
  qt3d/tests/auto/render/meshfunctors/tst_meshfunctors.cpp:50:10: note: candidate: ‘virtual bool MeshFunctorA::operator==(const Qt3DCore::QGeometryFactory&) const’
     50 |     bool operator ==(const Qt3DCore::QGeometryFactory &other) const override
        |          ^~~~~~~~

Fix by providing a symmetric operator== for QGeometryFactory that
delegates to a virtual equals() method.

Pick-to: 6.2 5.15
Change-Id: I23d29ad1b16075629132f2b4757c5810d5615a36
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

4 files changed, 8 insertions, 6 deletions

diff --git a/src/core/geometry/qgeometryfactory_p.h b/src/core/geometry/qgeometryfactory_p.h
index 47f3a5281..97114d658 100644
--- a/src/core/geometry/qgeometryfactory_p.h
+++ b/src/core/geometry/qgeometryfactory_p.h
@@ -66,7 +66,9 @@ class Q_3DCORESHARED_EXPORT QGeometryFactory : public QAbstractFunctor
 public:
     virtual ~QGeometryFactory();
     virtual QGeometry *operator()() = 0;
-    virtual bool operator ==(const QGeometryFactory &other) const = 0;
+    virtual bool equals(const QGeometryFactory &other) const = 0;
+    friend bool operator==(const QGeometryFactory &lhs, const QGeometryFactory &rhs)
+    { return lhs.equals(rhs); }
 };
 
 typedef QSharedPointer<QGeometryFactory> QGeometryFactoryPtr;
diff --git a/src/render/geometry/qmesh.cpp b/src/render/geometry/qmesh.cpp
index 1180380b0..9bcad868d 100644
--- a/src/render/geometry/qmesh.cpp
+++ b/src/render/geometry/qmesh.cpp
@@ -388,7 +388,7 @@ Qt3DCore::QGeometry *MeshLoaderFunctor::operator()()
 /*!
  * \internal
  */
-bool MeshLoaderFunctor::operator ==(const QGeometryFactory &other) const
+bool MeshLoaderFunctor::equals(const QGeometryFactory &other) const
 {
     const MeshLoaderFunctor *otherFunctor = functor_cast<MeshLoaderFunctor>(&other);
     if (otherFunctor != nullptr)
diff --git a/src/render/geometry/qmesh_p.h b/src/render/geometry/qmesh_p.h
index 9d34a6ae6..e38f5779b 100644
--- a/src/render/geometry/qmesh_p.h
+++ b/src/render/geometry/qmesh_p.h
@@ -119,7 +119,7 @@ public :
     QMesh::Status status() const { return m_status; }
 
     Qt3DCore::QGeometry *operator()() override;
-    bool operator ==(const Qt3DCore::QGeometryFactory &other) const override;
+    bool equals(const Qt3DCore::QGeometryFactory &other) const override;
     QT3D_FUNCTOR(MeshLoaderFunctor)
 
 private:
diff --git a/tests/auto/render/meshfunctors/tst_meshfunctors.cpp b/tests/auto/render/meshfunctors/tst_meshfunctors.cpp
index fc22b17f7..bf8d9f2af 100644
--- a/tests/auto/render/meshfunctors/tst_meshfunctors.cpp
+++ b/tests/auto/render/meshfunctors/tst_meshfunctors.cpp
@@ -47,7 +47,7 @@ public:
         return nullptr;
     }
 
-    bool operator ==(const Qt3DCore::QGeometryFactory &other) const override
+    bool equals(const Qt3DCore::QGeometryFactory &other) const override
     {
         return Qt3DCore::functor_cast<MeshFunctorA>(&other);
     }
@@ -69,7 +69,7 @@ public:
         return nullptr;
     }
 
-    bool operator ==(const Qt3DCore::QGeometryFactory &other) const override
+    bool equals(const Qt3DCore::QGeometryFactory &other) const override
     {
         return Qt3DCore::functor_cast<MeshFunctorB>(&other);
     }
@@ -86,7 +86,7 @@ public:
     ~MeshFunctorASub()
     {}
 
-    bool operator ==(const Qt3DCore::QGeometryFactory &other) const override
+    bool equals(const Qt3DCore::QGeometryFactory &other) const override
     {
         return Qt3DCore::functor_cast<MeshFunctorASub>(&other);
     }