Part: add helper class ShapeMapHasher to reduce conditional inclusions

src/Mod/Part/App/ShapeMapHasher.h

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+/***************************************************************************
+ *   Copyright (c) 2024 Werner Mayer <wmayer[at]users.sourceforge.net>     *
+ *                                                                         *
+ *   This file is part of FreeCAD.                                         *
+ *                                                                         *
+ *   FreeCAD is free software: you can redistribute it and/or modify it    *
+ *   under the terms of the GNU Lesser General Public License as           *
+ *   published by the Free Software Foundation, either version 2.1 of the  *
+ *   License, or (at your option) any later version.                       *
+ *                                                                         *
+ *   FreeCAD is distributed in the hope that it will be useful, but        *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
+ *   Lesser General Public License for more details.                       *
+ *                                                                         *
+ *   You should have received a copy of the GNU Lesser General Public      *
+ *   License along with FreeCAD. If not, see                               *
+ *   <https://www.gnu.org/licenses/>.                                      *
+ *                                                                         *
+ **************************************************************************/
+
+#ifndef PART_SHAPEMAPHASHER_H
+#define PART_SHAPEMAPHASHER_H
+
+#include <Standard_Version.hxx>
+#include <TopoDS_Shape.hxx>
+#if OCC_VERSION_HEX >= 0x070800
+#include <functional>
+#endif
+
+namespace Part {
+
+class ShapeMapHasher
+{
+public:
+    size_t operator()(const TopoDS_Shape& theShape) const
+    {
+#if OCC_VERSION_HEX < 0x070800
+        return theShape.HashCode(INT_MAX);
+#else
+        return std::hash<TopoDS_Shape>{}(theShape);
+#endif
+    }
+};
+
+}
+
+#endif  // PART_SHAPEMAPHASHER_H