diff --git a/src/App/Branding.cpp b/src/App/Branding.cpp
index a8b8eca594..6f593022a6 100644
--- a/src/App/Branding.cpp
+++ b/src/App/Branding.cpp
@@ -78,8 +78,8 @@ Branding::XmlConfig Branding::getUserDefines() const
     if (!root.isNull()) {
         child = root.firstChildElement();
         while (!child.isNull()) {
-            std::string name = (const char*)child.localName().toLatin1();
-            std::string value = (const char*)child.text().toUtf8();
+            std::string name = child.localName().toLatin1().constData();
+            std::string value = child.text().toUtf8().constData();
             if (std::find(filter.begin(), filter.end(), name) != filter.end())
                 cfg[name] = value;
             child = child.nextSiblingElement();
diff --git a/src/App/ComplexGeoData.cpp b/src/App/ComplexGeoData.cpp
index dc490bed13..992e1e8324 100644
--- a/src/App/ComplexGeoData.cpp
+++ b/src/App/ComplexGeoData.cpp
@@ -40,12 +40,12 @@ TYPESYSTEM_SOURCE_ABSTRACT(Data::Segment , Base::BaseClass)
 TYPESYSTEM_SOURCE_ABSTRACT(Data::ComplexGeoData , Base::Persistence)
 
 
-ComplexGeoData::ComplexGeoData(void)
+ComplexGeoData::ComplexGeoData()
     :Tag(0)
 {
 }
 
-ComplexGeoData::~ComplexGeoData(void)
+ComplexGeoData::~ComplexGeoData()
 {
 }
 
@@ -56,10 +56,10 @@ Data::Segment* ComplexGeoData::getSubElementByName(const char* name) const
     std::string::size_type pos = element.find_first_of("0123456789");
     if (pos != std::string::npos) {
         index = std::atoi(element.substr(pos).c_str());
-        element = element.substr(0,pos);
+        element = element.substr(0, pos);
     }
 
-    return getSubElement(element.c_str(),index);
+    return getSubElement(element.c_str(), static_cast<unsigned long>(index));
 }
 
 void ComplexGeoData::applyTransform(const Base::Matrix4D& rclTrf)
diff --git a/src/App/ComplexGeoData.h b/src/App/ComplexGeoData.h
index 875e9b309b..d8fb8e7d46 100644
--- a/src/App/ComplexGeoData.h
+++ b/src/App/ComplexGeoData.h
@@ -68,7 +68,7 @@ public:
     };
 
     /// Constructor
-    ComplexGeoData(void);
+    ComplexGeoData();
     /// Destructor
     virtual ~ComplexGeoData();
 
@@ -78,7 +78,7 @@ public:
      *  List of different subelement types
      *  its NOT a list of the subelements itself
      */
-    virtual std::vector<const char*> getElementTypes(void) const=0;
+    virtual std::vector<const char*> getElementTypes() const=0;
     virtual unsigned long countSubElements(const char* Type) const=0;
     /// get the subelement by type and number
     virtual Segment* getSubElement(const char* Type, unsigned long) const=0;
@@ -122,7 +122,7 @@ public:
      * This method has to be handled by the child classes.
      * the actual placement and matrix is not part of this class.
      */
-    virtual Base::Matrix4D getTransform(void) const = 0;
+    virtual Base::Matrix4D getTransform() const = 0;
     //@}
 
     /** @name Modification */
@@ -134,7 +134,7 @@ public:
     /** @name Getting basic geometric entities */
     //@{
     /// Get the bound box
-    virtual Base::BoundBox3d getBoundBox(void)const=0;
+    virtual Base::BoundBox3d getBoundBox()const=0;
     /** Get point from line object intersection  */
     virtual Base::Vector3d getPointFromLineIntersection(
         const Base::Vector3f& base,
@@ -196,7 +196,9 @@ protected:
     /// from local to outside
     inline Base::Vector3d transformToOutside(const Base::Vector3f& vec) const
     {
-        return getTransform() * Base::Vector3d(vec.x,vec.y,vec.z);
+        return getTransform() * Base::Vector3d(static_cast<double>(vec.x),
+                                               static_cast<double>(vec.y),
+                                               static_cast<double>(vec.z));
     }
     /// from local to inside
     inline Base::Vector3f transformToInside(const Base::Vector3d& vec) const
@@ -204,7 +206,9 @@ protected:
         Base::Matrix4D tmpM(getTransform());
         tmpM.inverse();
         Base::Vector3d tmp = tmpM * vec;
-        return Base::Vector3f((float)tmp.x,(float)tmp.y,(float)tmp.z);
+        return Base::Vector3f(static_cast<float>(tmp.x),
+                              static_cast<float>(tmp.y),
+                              static_cast<float>(tmp.z));
     }
 public:
     mutable long Tag;
diff --git a/src/App/DocumentObject.h b/src/App/DocumentObject.h
index 30ffe02880..77bb6e15f2 100644
--- a/src/App/DocumentObject.h
+++ b/src/App/DocumentObject.h
@@ -171,8 +171,8 @@ public:
     bool isRemoving() const {return StatusBits.test(ObjectStatus::Remove);}
     /// return the status bits
     unsigned long getStatus() const {return StatusBits.to_ulong();}
-    bool testStatus(ObjectStatus pos) const {return StatusBits.test((size_t)pos);}
-    void setStatus(ObjectStatus pos, bool on) {StatusBits.set((size_t)pos, on);}
+    bool testStatus(ObjectStatus pos) const {return StatusBits.test(size_t(pos));}
+    void setStatus(ObjectStatus pos, bool on) {StatusBits.set(size_t(pos), on);}
     //@}
 
     int isExporting() const;
diff --git a/src/App/Enumeration.cpp b/src/App/Enumeration.cpp
index 4855bc34a8..dc4a73bbda 100644
--- a/src/App/Enumeration.cpp
+++ b/src/App/Enumeration.cpp
@@ -160,7 +160,7 @@ void Enumeration::setEnums(const std::vector<std::string> &values)
     _EnumArray[i] = 0; // null termination
 
     // Other state variables
-    _maxVal = values.size() - 1;
+    _maxVal = static_cast<int>(values.size() - 1);
     _ownEnumArray = true;
     if (_index < 0)
         _index = 0;
diff --git a/src/App/Material.cpp b/src/App/Material.cpp
index 64590868c6..89ce94badf 100644
--- a/src/App/Material.cpp
+++ b/src/App/Material.cpp
@@ -35,7 +35,7 @@ using namespace App;
 //===========================================================================
 // Material
 //===========================================================================
-Material::Material(void)
+Material::Material()
 {
     setType(STEEL);
     setType(USER_DEFINED);
diff --git a/src/App/Material.h b/src/App/Material.h
index 90d44b070b..18f1f9f470 100644
--- a/src/App/Material.h
+++ b/src/App/Material.h
@@ -25,7 +25,7 @@
 #define APP_MATERIAL_H
 
 #ifdef __GNUC__
-# include <stdint.h>
+# include <cstdint>
 #endif
 
 #include <sstream>
@@ -100,10 +100,10 @@ public:
      */
     uint32_t getPackedValue() const
     {
-        return ((uint32_t)(r*255.0f + 0.5f) << 24 |
-                (uint32_t)(g*255.0f + 0.5f) << 16 |
-                (uint32_t)(b*255.0f + 0.5f) << 8  |
-                (uint32_t)(a*255.0f + 0.5f));
+        return (static_cast<uint32_t>(r*255.0f + 0.5f) << 24 |
+                static_cast<uint32_t>(g*255.0f + 0.5f) << 16 |
+                static_cast<uint32_t>(b*255.0f + 0.5f) << 8  |
+                static_cast<uint32_t>(a*255.0f + 0.5f));
     }
     /**
      * creates FC Color from template type, e.g. Qt QColor
@@ -116,8 +116,8 @@ public:
      *
      */
     template <typename T>
-    inline T asValue(void) const {
-        return(T(int(r*255.0),int(g*255.0),int(b*255.0)));
+    inline T asValue() const {
+        return(T(int(r*255.0f),int(g*255.0f),int(b*255.0f)));
     }
     /**
      * returns color as hex color "#RRGGBB"
@@ -125,9 +125,9 @@ public:
      */
     std::string asHexString() const {
         std::stringstream ss;
-        ss << "#" << std::hex << std::uppercase << std::setfill('0') << std::setw(2) << int(r*255.0)
-                                                                     << std::setw(2) << int(g*255.0)
-                                                                     << std::setw(2) << int(b*255.0);
+        ss << "#" << std::hex << std::uppercase << std::setfill('0') << std::setw(2) << int(r*255.0f)
+                                                                     << std::setw(2) << int(g*255.0f)
+                                                                     << std::setw(2) << int(b*255.0f);
         return ss.str();
     }
     /**
@@ -223,7 +223,7 @@ public:
      */
     //@{
     /** Sets the USER_DEFINED material type. The user must set the colors afterwards. */
-    Material(void);
+    Material();
     /** Defines the colors and shininess for the material \a MatName. If \a MatName isn't defined then USER_DEFINED is
      * set and the user must define the colors itself.
      */
diff --git a/src/App/PropertyFile.cpp b/src/App/PropertyFile.cpp
index 5c14e43bae..368eef20fb 100644
--- a/src/App/PropertyFile.cpp
+++ b/src/App/PropertyFile.cpp
@@ -64,7 +64,7 @@ PropertyFileIncluded::~PropertyFileIncluded()
     }
 }
 
-void PropertyFileIncluded::aboutToSetValue(void)
+void PropertyFileIncluded::aboutToSetValue()
 {
     // This is a trick to check in Copy() if it is called
     // directly from outside or by the Undo/Redo mechanism.
@@ -78,7 +78,7 @@ void PropertyFileIncluded::aboutToSetValue(void)
     this->StatusBits.reset(10);
 }
 
-std::string PropertyFileIncluded::getDocTransientPath(void) const
+std::string PropertyFileIncluded::getDocTransientPath() const
 {
     std::string path;
     PropertyContainer *co = getContainer();
@@ -100,13 +100,13 @@ std::string PropertyFileIncluded::getUniqueFileName(const std::string& path, con
     return fi.filePath();
 }
 
-std::string PropertyFileIncluded::getExchangeTempFile(void) const
+std::string PropertyFileIncluded::getExchangeTempFile() const
 {
     return Base::FileInfo::getTempFileName(Base::FileInfo
         (getValue()).fileName().c_str(), getDocTransientPath().c_str());
 }
 
-std::string PropertyFileIncluded::getOriginalFileName(void) const
+std::string PropertyFileIncluded::getOriginalFileName() const
 {
     return _OriginalName;
 }
@@ -232,14 +232,14 @@ void PropertyFileIncluded::setValue(const char* sFile, const char* sName)
     }
 }
 
-const char* PropertyFileIncluded::getValue(void) const
+const char* PropertyFileIncluded::getValue() const
 {
      return _cValue.c_str();
 }
 
-PyObject *PropertyFileIncluded::getPyObject(void)
+PyObject *PropertyFileIncluded::getPyObject()
 {
-    PyObject *p = PyUnicode_DecodeUTF8(_cValue.c_str(),_cValue.size(),0);
+    PyObject *p = PyUnicode_DecodeUTF8(_cValue.c_str(),_cValue.size(),nullptr);
     if (!p) {
         throw Base::UnicodeError("PropertyFileIncluded: UTF-8 conversion failure");
     }
@@ -249,7 +249,7 @@ PyObject *PropertyFileIncluded::getPyObject(void)
 namespace App {
 const char* getNameFromFile(PyObject* value)
 {
-    const char* string = 0;
+    const char* string = nullptr;
     PyObject *oname = PyObject_GetAttrString (value, "name");
     if (oname) {
         if (PyUnicode_Check (oname)) {
@@ -464,7 +464,7 @@ void PropertyFileIncluded::RestoreDocFile(Base::Reader &reader)
     hasSetValue();
 }
 
-Property *PropertyFileIncluded::Copy(void) const
+Property *PropertyFileIncluded::Copy() const
 {
     std::unique_ptr<PropertyFileIncluded> prop(new PropertyFileIncluded());
 
@@ -564,7 +564,7 @@ void PropertyFileIncluded::Paste(const Property &from)
     hasSetValue();
 }
 
-unsigned int PropertyFileIncluded::getMemSize (void) const
+unsigned int PropertyFileIncluded::getMemSize () const
 {
     unsigned int mem = Property::getMemSize();
     mem += _cValue.size();
diff --git a/src/App/PropertyFile.h b/src/App/PropertyFile.h
index f512ae4522..97061023f4 100644
--- a/src/App/PropertyFile.h
+++ b/src/App/PropertyFile.h
@@ -44,10 +44,10 @@ class AppExport PropertyFile : public PropertyString
     TYPESYSTEM_HEADER();
 
 public:
-    PropertyFile(void);
+    PropertyFile();
     virtual ~PropertyFile();
 
-    virtual const char* getEditorName(void) const
+    virtual const char* getEditorName() const
     { return "Gui::PropertyEditor::PropertyFileItem"; }
 
     virtual void setFilter(const std::string filter);
@@ -76,15 +76,15 @@ class AppExport PropertyFileIncluded : public Property
     TYPESYSTEM_HEADER();
 
 public:
-    PropertyFileIncluded(void);
+    PropertyFileIncluded();
     virtual ~PropertyFileIncluded();
 
-    void setValue(const char* sFile, const char* sName=0);
-    const char* getValue(void) const;
+    void setValue(const char* sFile, const char* sName=nullptr);
+    const char* getValue() const;
 
-    virtual const char* getEditorName(void) const
+    virtual const char* getEditorName() const
     { return "Gui::PropertyEditor::PropertyTransientFileItem"; }
-    virtual PyObject *getPyObject(void);
+    virtual PyObject *getPyObject();
     virtual void setPyObject(PyObject *);
     
     virtual void Save (Base::Writer &writer) const;
@@ -93,9 +93,9 @@ public:
     virtual void SaveDocFile (Base::Writer &writer) const;
     virtual void RestoreDocFile(Base::Reader &reader);
 
-    virtual Property *Copy(void) const;
+    virtual Property *Copy() const;
     virtual void Paste(const Property &from);
-    virtual unsigned int getMemSize (void) const;
+    virtual unsigned int getMemSize () const;
 
     virtual bool isSame(const Property &other) const {
         if (&other == this)
@@ -111,16 +111,16 @@ public:
       * this file with setValue() is the fastest way to change
       * the File.
       */
-    std::string getExchangeTempFile(void) const;
-    std::string getOriginalFileName(void) const;
+    std::string getExchangeTempFile() const;
+    std::string getOriginalFileName() const;
 
     bool isEmpty(void) const {return _cValue.empty();}
 
 protected:
     // get the transient path if the property is in a DocumentObject
-    std::string getDocTransientPath(void) const;
+    std::string getDocTransientPath() const;
     std::string getUniqueFileName(const std::string&, const std::string&) const;
-    void aboutToSetValue(void);
+    void aboutToSetValue();
 
 protected:
     mutable std::string _cValue;
diff --git a/src/App/PropertyUnits.cpp b/src/App/PropertyUnits.cpp
index 61d21f036f..403211ff1b 100644
--- a/src/App/PropertyUnits.cpp
+++ b/src/App/PropertyUnits.cpp
@@ -74,7 +74,7 @@ Base::Quantity PropertyQuantity::createQuantityFromPy(PyObject *value)
     else if (PyFloat_Check(value))
         quant = Quantity(PyFloat_AsDouble(value),_Unit);
     else if (PyLong_Check(value))
-        quant = Quantity((double)PyLong_AsLong(value),_Unit);
+        quant = Quantity(double(PyLong_AsLong(value)),_Unit);
     else if (PyObject_TypeCheck(value, &(QuantityPy::Type))) {
         Base::QuantityPy  *pcObject = static_cast<Base::QuantityPy*>(value);
         quant = *(pcObject->getQuantityPtr());
diff --git a/src/App/Range.cpp b/src/App/Range.cpp
index ce5d360b34..7a0fb891e8 100644
--- a/src/App/Range.cpp
+++ b/src/App/Range.cpp
@@ -42,9 +42,9 @@ Range::Range(const char * range)
     std::string from;
     std::string to;
 
-    assert(range != NULL);
+    assert(range != nullptr);
 
-    if (strchr(range, ':') == NULL) {
+    if (strchr(range, ':') == nullptr) {
         from = range;
         to = range;
     }
@@ -247,13 +247,13 @@ std::string App::CellAddress::toString(Cell cell) const
         if (_absCol && flags.testFlag(Cell::Absolute))
             s << '$';
         if (col() < 26) {
-            s << (char)('A' + col());
+            s << static_cast<char>('A' + col());
         }
         else {
             int colnum = col() - 26;
 
-            s << (char)('A' + (colnum / 26));
-            s << (char)('A' + (colnum % 26));
+            s << static_cast<char>('A' + (colnum / 26));
+            s << static_cast<char>('A' + (colnum % 26));
         }
     }
 
diff --git a/src/Base/FileInfo.cpp b/src/Base/FileInfo.cpp
index f0b45273c8..1413a419ac 100644
--- a/src/Base/FileInfo.cpp
+++ b/src/Base/FileInfo.cpp
@@ -66,9 +66,9 @@ using namespace Base;
 std::string ConvertFromWideString(const std::wstring& string)
 {
     int neededSize = WideCharToMultiByte(CP_UTF8, 0, string.c_str(), -1, 0, 0,0,0);
-    char * CharString = new char[neededSize];
+    char * CharString = new char[static_cast<size_t>(neededSize)];
     WideCharToMultiByte(CP_UTF8, 0, string.c_str(), -1, CharString, neededSize,0,0);
-    std::string String((char*)CharString);
+    std::string String(CharString);
     delete [] CharString;
     CharString = NULL;
     return String;
@@ -77,7 +77,7 @@ std::string ConvertFromWideString(const std::wstring& string)
 std::wstring ConvertToWideString(const std::string& string)
 {
     int neededSize = MultiByteToWideChar(CP_UTF8, 0, string.c_str(), -1, 0, 0);
-    wchar_t* wideCharString = new wchar_t[neededSize];
+    wchar_t* wideCharString = new wchar_t[static_cast<size_t>(neededSize)];
     MultiByteToWideChar(CP_UTF8, 0, string.c_str(), -1, wideCharString, neededSize);
     std::wstring wideString(wideCharString);
     delete [] wideCharString;
@@ -110,7 +110,7 @@ const std::string &FileInfo::getTempPath()
         wchar_t buf[MAX_PATH + 2];
         GetTempPathW(MAX_PATH + 1,buf);
         int neededSize = WideCharToMultiByte(CP_UTF8, 0, buf, -1, 0, 0, 0, 0);
-        char* dest = new char[neededSize];
+        char* dest = new char[static_cast<size_t>(neededSize)];
         WideCharToMultiByte(CP_UTF8, 0, buf, -1,dest, neededSize, 0, 0);
         tempPath = dest;
         delete [] dest;
@@ -383,14 +383,15 @@ bool FileInfo::isDir () const
             return false;
         }
         return S_ISDIR(st.st_mode);
-#endif
+#else
         return false;
+#endif
     }
     else
         return false;
 
     // TODO: Check for valid path name
-    return true;
+    //return true;
 }
 
 unsigned int FileInfo::size () const
diff --git a/src/Base/FutureWatcherProgress.cpp b/src/Base/FutureWatcherProgress.cpp
index 35573d37b9..c151cd8924 100644
--- a/src/Base/FutureWatcherProgress.cpp
+++ b/src/Base/FutureWatcherProgress.cpp
@@ -40,7 +40,7 @@ void FutureWatcherProgress::progressValueChanged(int v)
 {
     if (steps == 0)
         return;
-    unsigned int step = (100 * v) / steps;
+    unsigned int step = (100 * static_cast<unsigned int>(v)) / steps;
     if (step > current) {
         current = step;
         seq.next();
diff --git a/src/Base/GeometryPyCXX.cpp b/src/Base/GeometryPyCXX.cpp
index 151c043b00..5d6fafb789 100644
--- a/src/Base/GeometryPyCXX.cpp
+++ b/src/Base/GeometryPyCXX.cpp
@@ -127,7 +127,8 @@ Py::Object Vector2dPy::repr()
     Py::Float y(v.y);
     std::stringstream str;
     str << "Vector2 (";
-    str << (std::string)x.repr() << ", "<< (std::string)y.repr();
+    str << static_cast<std::string>(x.repr()) << ", "
+        << static_cast<std::string>(y.repr());
     str << ")";
 
     return Py::String(str.str());
diff --git a/src/Base/InputSource.cpp b/src/Base/InputSource.cpp
index ef959b730d..da3f49af3a 100644
--- a/src/Base/InputSource.cpp
+++ b/src/Base/InputSource.cpp
@@ -89,28 +89,28 @@ unsigned int StdInputStream::readBytes( XMLByte* const  toFill, const unsigned i
 #else
 XMLFilePos StdInputStream::curPos() const
 {
-  return stream.tellg();
+  return static_cast<XMLFilePos>(stream.tellg());
 }
 
-XMLSize_t StdInputStream::readBytes( XMLByte* const  toFill, const XMLSize_t maxToRead )
+XMLSize_t StdInputStream::readBytes(XMLByte* const  toFill, const XMLSize_t maxToRead)
 {
   //
   //  Read up to the maximum bytes requested. We return the number
   //  actually read.
   //
 
-  stream.read((char *)toFill,maxToRead);
-  XMLSize_t len = stream.gcount();
+  stream.read(reinterpret_cast<char *>(toFill), static_cast<std::streamsize>(maxToRead));
+  std::streamsize len = stream.gcount();
 
   QTextCodec *codec = QTextCodec::codecForName("UTF-8");
-  const QString text = codec->toUnicode((char *)toFill, len, &state);
+  const QString text = codec->toUnicode(reinterpret_cast<char *>(toFill), static_cast<int>(len), &state);
   if (state.invalidChars > 0) {
       // In case invalid characters were found decode back to 'utf-8' and replace
       // them with '?'
       // First, Qt replaces invalid characters with '\0' (see ConvertInvalidToNull)
       // but Xerces doesn't like this because it handles this as termination. Thus,
       // we have to go through the array and replace '\0' with '?'.
-      XMLSize_t pos = 0;
+      std::streamsize pos = 0;
       QByteArray ba = codec->fromUnicode(text);
       for (int i=0; i<ba.length(); i++, pos++) {
           if (pos < len && ba[i] == '\0')
@@ -118,7 +118,7 @@ XMLSize_t StdInputStream::readBytes( XMLByte* const  toFill, const XMLSize_t max
       }
   }
 
-  return len;
+  return static_cast<XMLSize_t>(len);
 }
 #endif
 
diff --git a/src/Base/PlacementPyImp.cpp b/src/Base/PlacementPyImp.cpp
index 15789ae5e4..3ed96ad601 100644
--- a/src/Base/PlacementPyImp.cpp
+++ b/src/Base/PlacementPyImp.cpp
@@ -289,16 +289,16 @@ void PlacementPy::setRotation(Py::Object arg)
 {
     Py::Rotation rot;
     if (rot.accepts(arg.ptr())) {
-        getPlacementPtr()->setRotation((Base::Rotation)Py::Rotation(arg));
+        getPlacementPtr()->setRotation(static_cast<Base::Rotation>(Py::Rotation(arg)));
         return;
     }
     Py::Tuple tuple;
     if (tuple.accepts(arg.ptr())) {
         tuple = arg;
-        getPlacementPtr()->setRotation(Base::Rotation((double)Py::Float(tuple[0]),
-                                                      (double)Py::Float(tuple[1]),
-                                                      (double)Py::Float(tuple[2]),
-                                                      (double)Py::Float(tuple[3])
+        getPlacementPtr()->setRotation(Base::Rotation(static_cast<double>(Py::Float(tuple[0])),
+                                                      static_cast<double>(Py::Float(tuple[1])),
+                                                      static_cast<double>(Py::Float(tuple[2])),
+                                                      static_cast<double>(Py::Float(tuple[3]))
                                                      ));
         return;
     }
diff --git a/src/Base/Quantity.cpp b/src/Base/Quantity.cpp
index 9b8fe17663..b92aa8073e 100644
--- a/src/Base/Quantity.cpp
+++ b/src/Base/Quantity.cpp
@@ -438,12 +438,21 @@ double num_change(char* yytext,char dez_delim,char grp_delim)
     return ret_val;
 }
 
+#if defined(__clang__)
+# pragma clang diagnostic push
+# pragma clang diagnostic ignored "-Wmissing-noreturn"
+#endif
+
 // error func
 void Quantity_yyerror(char *errorinfo)
 {
     throw Base::ParserError(errorinfo);
 }
 
+#if defined(__clang__)
+# pragma clang diagnostic pop
+#endif
+
 
 // for VC9 (isatty and fileno not supported anymore)
 //#ifdef _MSC_VER
diff --git a/src/Base/QuantityPyImp.cpp b/src/Base/QuantityPyImp.cpp
index a4354fe2ce..43d09240a5 100644
--- a/src/Base/QuantityPyImp.cpp
+++ b/src/Base/QuantityPyImp.cpp
@@ -115,8 +115,15 @@ int QuantityPy::PyInit(PyObject* args, PyObject* /*kwd*/)
     int i8=0;
     PyErr_Clear(); // set by PyArg_ParseTuple()
     if (PyArg_ParseTuple(args, "|diiiiiiii", &f,&i1,&i2,&i3,&i4,&i5,&i6,&i7,&i8)) {
-        if (f != DOUBLE_MAX) {
-            *self = Quantity(f,Unit(i1,i2,i3,i4,i5,i6,i7,i8));
+        if (f < DOUBLE_MAX) {
+            *self = Quantity(f,Unit{static_cast<int8_t>(i1),
+                                    static_cast<int8_t>(i2),
+                                    static_cast<int8_t>(i3),
+                                    static_cast<int8_t>(i4),
+                                    static_cast<int8_t>(i5),
+                                    static_cast<int8_t>(i6),
+                                    static_cast<int8_t>(i7),
+                                    static_cast<int8_t>(i8)});
         }
         return 0;
     }
@@ -218,8 +225,15 @@ PyObject* QuantityPy::getValueAs(PyObject *args)
         int i8=0;
         PyErr_Clear();
         if (PyArg_ParseTuple(args, "d|iiiiiiii", &f,&i1,&i2,&i3,&i4,&i5,&i6,&i7,&i8)) {
-            if (f!=DOUBLE_MAX) {
-                quant = Quantity(f,Unit(i1,i2,i3,i4,i5,i6,i7,i8));
+            if (f < DOUBLE_MAX) {
+                quant = Quantity(f,Unit{static_cast<int8_t>(i1),
+                                        static_cast<int8_t>(i2),
+                                        static_cast<int8_t>(i3),
+                                        static_cast<int8_t>(i4),
+                                        static_cast<int8_t>(i5),
+                                        static_cast<int8_t>(i6),
+                                        static_cast<int8_t>(i7),
+                                        static_cast<int8_t>(i8)});
             }
         }
     }
@@ -278,7 +292,7 @@ PyObject * QuantityPy::number_int_handler (PyObject *self)
     }
 
     QuantityPy* q = static_cast<QuantityPy*>(self);
-    return PyLong_FromLong((long)q->getValue());
+    return PyLong_FromLong(long(q->getValue()));
 }
 
 PyObject * QuantityPy::number_negative_handler (PyObject *self)
diff --git a/src/Base/Rotation.cpp b/src/Base/Rotation.cpp
index a3bb128e8b..2edd5bd5f1 100644
--- a/src/Base/Rotation.cpp
+++ b/src/Base/Rotation.cpp
@@ -515,7 +515,7 @@ Rotation Rotation::makeRotationByAxes(Vector3d xdir, Vector3d ydir, Vector3d zdi
 
 
     auto dropPriority = [&order](int index){
-        char tmp;
+        int tmp;
         if (index == 0){
             tmp = order[0];
             order[0] = order[1];
@@ -531,7 +531,7 @@ Rotation Rotation::makeRotationByAxes(Vector3d xdir, Vector3d ydir, Vector3d zdi
     //pick up the strict direction
     Vector3d mainDir;
     for (int i = 0; i < 3; ++i){
-        mainDir = *(dirs[order[0]]);
+        mainDir = *(dirs[size_t(order[0])]);
         if (mainDir.Length() > tol)
             break;
         else
@@ -544,7 +544,7 @@ Rotation Rotation::makeRotationByAxes(Vector3d xdir, Vector3d ydir, Vector3d zdi
     //pick up the 2nd priority direction, "hint" direction.
     Vector3d hintDir;
     for (int i = 0; i < 2; ++i){
-        hintDir = *(dirs[order[1]]);
+        hintDir = *(dirs[size_t(order[1])]);
         if ((hintDir.Cross(mainDir)).Length() > tol)
             break;
         else
diff --git a/src/Base/Tools.cpp b/src/Base/Tools.cpp
index ad12e7d7cb..eee272bd9b 100644
--- a/src/Base/Tools.cpp
+++ b/src/Base/Tools.cpp
@@ -166,7 +166,7 @@ std::string Base::Tools::escapedUnicodeToUtf8(const std::string& s)
     Base::PyGILStateLocker lock;
     std::string string;
 
-    PyObject* unicode = PyUnicode_DecodeUnicodeEscape(s.c_str(), s.size(), "strict");
+    PyObject* unicode = PyUnicode_DecodeUnicodeEscape(s.c_str(), static_cast<Py_ssize_t>(s.size()), "strict");
     if (!unicode)
         return string;
     if (PyUnicode_Check(unicode)) {
diff --git a/src/Base/Tools.h b/src/Base/Tools.h
index be28e62183..79a21cf623 100644
--- a/src/Base/Tools.h
+++ b/src/Base/Tools.h
@@ -263,14 +263,19 @@ struct BaseExport Tools
      * @param s String to convert.
      * @return A std::string encoded as UTF-8.
      */
-    static inline std::string toStdString(const QString& s) { QByteArray tmp = s.toUtf8(); return std::string(tmp.constData(), tmp.size()); }
+    static inline std::string toStdString(const QString& s) {
+        QByteArray tmp = s.toUtf8();
+        return std::string(tmp.constData(), static_cast<size_t>(tmp.size()));
+    }
 
     /**
      * @brief fromStdString Convert a std::string encoded as UTF-8 into a QString.
      * @param s std::string, expected to be UTF-8 encoded.
      * @return String represented as a QString.
      */
-    static inline QString fromStdString(const std::string & s) { return QString::fromUtf8(s.c_str(), s.size()); }
+    static inline QString fromStdString(const std::string & s) {
+        return QString::fromUtf8(s.c_str(), static_cast<int>(s.size()));
+    }
 };
 
 
diff --git a/src/Base/Tools2D.cpp b/src/Base/Tools2D.cpp
index e988b9c19d..14ef848496 100644
--- a/src/Base/Tools2D.cpp
+++ b/src/Base/Tools2D.cpp
@@ -43,7 +43,7 @@ double Vector2d::GetAngle (const Vector2d &rclVect) const
   {
     fNum = (*this * rclVect) / fDivid;
     if (fNum < -1)
-      return F_PI;
+      return D_PI;
     else
       if (fNum > 1)
         return 0.0;
@@ -186,11 +186,11 @@ bool Line2d::Intersect (const Line2d& rclLine, Vector2d &rclV) const
   if (fabs (clV2.x - clV1.x) > 1e-10)
     m1 = (clV2.y - clV1.y) / (clV2.x - clV1.x);
   else
-    m1 = FLOAT_MAX;
+    m1 = DOUBLE_MAX;
   if (fabs (rclLine.clV2.x - rclLine.clV1.x) > 1e-10)
     m2 = (rclLine.clV2.y - rclLine.clV1.y) / (rclLine.clV2.x - rclLine.clV1.x);
   else
-    m2 = FLOAT_MAX;
+    m2 = DOUBLE_MAX;
   if (m1 == m2)     /****** RETURN ERR (parallel lines) *************/
     return false;
 
@@ -198,13 +198,13 @@ bool Line2d::Intersect (const Line2d& rclLine, Vector2d &rclV) const
   b2 = rclLine.clV1.y - m2 * rclLine.clV1.x;
 
   // calc intersection
-  if (m1 == FLOAT_MAX)
+  if (m1 == DOUBLE_MAX)
   {
     rclV.x = clV1.x;
     rclV.y = m2 * rclV.x + b2;
   }
   else
-  if (m2 == FLOAT_MAX)
+  if (m2 == DOUBLE_MAX)
   {
     rclV.x = rclLine.clV1.x;
     rclV.y = m1 * rclV.x + b1;
diff --git a/src/Base/Tools2D.h b/src/Base/Tools2D.h
index 752ee1a566..c503500660 100644
--- a/src/Base/Tools2D.h
+++ b/src/Base/Tools2D.h
@@ -176,8 +176,10 @@ public:
   // admin-interface
   inline size_t GetCtVectors () const;
   inline bool Add (const Vector2d &rclVct);
-  inline Vector2d& operator[] (size_t ulNdx) const;
-  inline Vector2d& At (size_t ulNdx) const;
+  inline const Vector2d& operator[] (size_t ulNdx) const;
+  inline const Vector2d& At (size_t ulNdx) const;
+  inline Vector2d& operator[] (size_t ulNdx);
+  inline Vector2d& At (size_t ulNdx);
   inline bool Delete (size_t ulNdx);
   inline void  DeleteAll ();
 
@@ -200,7 +202,7 @@ inline Vector2d::Vector2d()
 }
 
 inline Vector2d::Vector2d(float x, float y)
-: x(x), y(y)
+: x(double(x)), y(double(y))
 {
 }
 
@@ -410,7 +412,8 @@ inline bool Polygon2d::Delete (size_t ulNdx)
 {
   if ( ulNdx < _aclVct.size() )
   {
-    std::vector<Vector2d>::iterator it = _aclVct.begin() + ulNdx;
+    std::vector<Vector2d>::iterator it = _aclVct.begin();
+    std::advance(it, ulNdx);
     _aclVct.erase ( it );
     return true;
   }
@@ -418,16 +421,27 @@ inline bool Polygon2d::Delete (size_t ulNdx)
   return false;
 }
 
-inline Vector2d& Polygon2d::operator[] (size_t ulNdx) const
+inline const Vector2d& Polygon2d::operator[] (size_t ulNdx) const
 {
-  return (Vector2d&) _aclVct[ulNdx];
+  return _aclVct[ulNdx];
 }
 
-inline Vector2d& Polygon2d::At (size_t ulNdx) const
+inline const Vector2d& Polygon2d::At (size_t ulNdx) const
 {
-  return (Vector2d&) _aclVct[ulNdx];
+  return _aclVct.at(ulNdx);
 }
 
+inline Vector2d& Polygon2d::operator[] (size_t ulNdx)
+{
+  return _aclVct[ulNdx];
+}
+
+inline Vector2d& Polygon2d::At (size_t ulNdx)
+{
+  return _aclVct.at(ulNdx);
+}
+
+
 inline Line2d::Line2d (const Line2d &rclLine)
     : clV1 (rclLine.clV1),
       clV2 (rclLine.clV2)
diff --git a/src/Base/Type.cpp b/src/Base/Type.cpp
index 6922d49088..dd97820655 100644
--- a/src/Base/Type.cpp
+++ b/src/Base/Type.cpp
@@ -142,7 +142,7 @@ Type Type::badType()
 const Type Type::createType(const Type parent, const char *name, instantiationMethod method)
 {
   Type newType;
-  newType.index = Type::typedata.size();
+  newType.index = static_cast<unsigned int>(Type::typedata.size());
   TypeData * typeData = new TypeData(name, newType, parent,method);
   Type::typedata.push_back(typeData);
 
@@ -232,7 +232,7 @@ int Type::getAllDerivedFrom(const Type type, std::vector<Type> & List)
 
 int Type::getNumTypes()
 {
-  return typedata.size();
+  return static_cast<int>(typedata.size());
 }
 
 Type Type::getTypeIfDerivedFrom(const char* name , const Type parent, bool bLoadModule)
diff --git a/src/Base/Unit.cpp b/src/Base/Unit.cpp
index d67a26522d..596e072dd1 100644
--- a/src/Base/Unit.cpp
+++ b/src/Base/Unit.cpp
@@ -65,14 +65,14 @@ Unit::Unit(int8_t Length,
            int8_t Angle)
 {
     checkRange("unit",
-               (int32_t)Length,
-               (int32_t)Mass,
-               (int32_t)Time,
-               (int32_t)ElectricCurrent,
-               (int32_t)ThermodynamicTemperature,
-               (int32_t)AmountOfSubstance,
-               (int32_t)LuminousIntensity,
-               (int32_t)Angle);
+               Length,
+               Mass,
+               Time,
+               ElectricCurrent,
+               ThermodynamicTemperature,
+               AmountOfSubstance,
+               LuminousIntensity,
+               Angle);
 
     Sig.Length                   = Length;
     Sig.Mass                     = Mass;
@@ -122,14 +122,14 @@ Unit::Unit(const QString& expr)
 Unit Unit::pow(signed char exp) const
 {
     checkRange("pow()",
-               (int32_t)Sig.Length * (int32_t)exp,
-               (int32_t)Sig.Mass * (int32_t)exp,
-               (int32_t)Sig.Time * (int32_t)exp,
-               (int32_t)Sig.ElectricCurrent * (int32_t)exp,
-               (int32_t)Sig.ThermodynamicTemperature * (int32_t)exp,
-               (int32_t)Sig.AmountOfSubstance * (int32_t)exp,
-               (int32_t)Sig.LuminousIntensity * (int32_t)exp,
-               (int32_t)Sig.Angle * (int32_t)exp);
+               Sig.Length * exp,
+               Sig.Mass * exp,
+               Sig.Time * exp,
+               Sig.ElectricCurrent * exp,
+               Sig.ThermodynamicTemperature * exp,
+               Sig.AmountOfSubstance * exp,
+               Sig.LuminousIntensity * exp,
+               Sig.Angle * exp);
 
     Unit result;
     result.Sig.Length                   = Sig.Length                    * exp;
@@ -172,14 +172,14 @@ bool Unit::operator ==(const Unit& that) const
 Unit Unit::operator *(const Unit &right) const
 {
     checkRange("* operator",
-               (int32_t)Sig.Length + (int32_t)right.Sig.Length,
-               (int32_t)Sig.Mass + (int32_t)right.Sig.Mass,
-               (int32_t)Sig.Time + (int32_t)right.Sig.Time,
-               (int32_t)Sig.ElectricCurrent + (int32_t)right.Sig.ElectricCurrent,
-               (int32_t)Sig.ThermodynamicTemperature + (int32_t)right.Sig.ThermodynamicTemperature,
-               (int32_t)Sig.AmountOfSubstance + (int32_t)right.Sig.AmountOfSubstance,
-               (int32_t)Sig.LuminousIntensity + (int32_t)right.Sig.LuminousIntensity,
-               (int32_t)Sig.Angle + (int32_t)right.Sig.Angle);
+               Sig.Length +right.Sig.Length,
+               Sig.Mass + right.Sig.Mass,
+               Sig.Time + right.Sig.Time,
+               Sig.ElectricCurrent + right.Sig.ElectricCurrent,
+               Sig.ThermodynamicTemperature + right.Sig.ThermodynamicTemperature,
+               Sig.AmountOfSubstance + right.Sig.AmountOfSubstance,
+               Sig.LuminousIntensity + right.Sig.LuminousIntensity,
+               Sig.Angle + right.Sig.Angle);
 
     Unit result;
     result.Sig.Length                   = Sig.Length                    + right.Sig.Length;
@@ -197,14 +197,14 @@ Unit Unit::operator *(const Unit &right) const
 Unit Unit::operator /(const Unit &right) const
 {
     checkRange("/ operator",
-               (int32_t)Sig.Length - (int32_t)right.Sig.Length,
-               (int32_t)Sig.Mass - (int32_t)right.Sig.Mass,
-               (int32_t)Sig.Time - (int32_t)right.Sig.Time,
-               (int32_t)Sig.ElectricCurrent - (int32_t)right.Sig.ElectricCurrent,
-               (int32_t)Sig.ThermodynamicTemperature - (int32_t)right.Sig.ThermodynamicTemperature,
-               (int32_t)Sig.AmountOfSubstance - (int32_t)right.Sig.AmountOfSubstance,
-               (int32_t)Sig.LuminousIntensity - (int32_t)right.Sig.LuminousIntensity,
-               (int32_t)Sig.Angle - (int32_t)right.Sig.Angle);
+               Sig.Length - right.Sig.Length,
+               Sig.Mass - right.Sig.Mass,
+               Sig.Time - right.Sig.Time,
+               Sig.ElectricCurrent - right.Sig.ElectricCurrent,
+               Sig.ThermodynamicTemperature - right.Sig.ThermodynamicTemperature,
+               Sig.AmountOfSubstance - right.Sig.AmountOfSubstance,
+               Sig.LuminousIntensity - right.Sig.LuminousIntensity,
+               Sig.Angle - right.Sig.Angle);
 
     Unit result;
     result.Sig.Length                   = Sig.Length                    - right.Sig.Length;
diff --git a/src/Base/UnitsApiPy.cpp b/src/Base/UnitsApiPy.cpp
index e391c1fb5b..7951e22b92 100644
--- a/src/Base/UnitsApiPy.cpp
+++ b/src/Base/UnitsApiPy.cpp
@@ -140,7 +140,7 @@ PyObject* UnitsApi::sSetSchema(PyObject * /*self*/, PyObject *args)
             PyErr_SetString(PyExc_ValueError, "invalid schema value");
             return nullptr;
         }
-        setSchema((UnitSystem)index);
+        setSchema(static_cast<UnitSystem>(index));
     }
     Py_Return;
 }
diff --git a/src/Base/UnitsSchema.cpp b/src/Base/UnitsSchema.cpp
index 25b6ec5b7c..df551bc83f 100644
--- a/src/Base/UnitsSchema.cpp
+++ b/src/Base/UnitsSchema.cpp
@@ -40,7 +40,7 @@ QString UnitsSchema::toLocale(const Base::Quantity& quant, double factor, const
     QLocale Lc;
     const QuantityFormat& format = quant.getFormat();
     if (format.option != QuantityFormat::None) {
-        uint opt = static_cast<uint>(format.option);
+        int opt = format.option;
         Lc.setNumberOptions(static_cast<QLocale::NumberOptions>(opt));
     }
 
diff --git a/src/Base/UnitsSchemaImperial1.cpp b/src/Base/UnitsSchemaImperial1.cpp
index 3cd062fe4d..02a3a3f370 100644
--- a/src/Base/UnitsSchemaImperial1.cpp
+++ b/src/Base/UnitsSchemaImperial1.cpp
@@ -235,18 +235,18 @@ QString UnitsSchemaImperialBuilding::schemaTranslate(const Quantity &quant, doub
         minden = quant.getFormat().getDenominator();
 
         // Compute and round the total number of fractional units
-        ntot = (int)std::round(totalInches * (double)minden);
+        ntot = static_cast<int>(std::round(totalInches * static_cast<double>(minden)));
 
         // If this is zero, nothing to do but return
         if( ntot==0 )
             return QString::fromLatin1("0");
 
         // Compute the whole number of feet and remaining units
-        feet = (int)std::floor(ntot / (12*minden));
+        feet = static_cast<int>(std::floor(ntot / (12*minden)));
         ntot = ntot - 12*minden*feet;
 
         // Compute the remaining number of whole inches
-        inches = (int)std::floor(ntot/minden);
+        inches = static_cast<int>(std::floor(ntot/minden));
 
         // Lastly the fractional quantities
         num = ntot - inches*minden;
@@ -387,9 +387,9 @@ QString UnitsSchemaImperialCivil::schemaTranslate(const Base::Quantity& quant, d
 //        double wholeSeconds = std::floor(rawSeconds);
 //        double remainSeconds = rawSeconds - wholeSeconds;
 
-        int outDeg = (int) wholeDegrees;
-        int outMin = (int) wholeMinutes;
-        int outSec = (int) std::round(rawSeconds);
+        int outDeg = static_cast<int>(wholeDegrees);
+        int outMin = static_cast<int>(wholeMinutes);
+        int outSec = static_cast<int>(std::round(rawSeconds));
 
         std::stringstream output;
         output << outDeg << degreeString.toUtf8().constData();
diff --git a/src/Base/VectorPyImp.cpp b/src/Base/VectorPyImp.cpp
index c79d5920d4..9e52fab521 100644
--- a/src/Base/VectorPyImp.cpp
+++ b/src/Base/VectorPyImp.cpp
@@ -47,7 +47,9 @@ std::string VectorPy::representation() const
     Py::Float z(ptr->z);
     std::stringstream str;
     str << "Vector (";
-    str << (std::string)x.repr() << ", "<< (std::string)y.repr() << ", "<< (std::string)z.repr();
+    str << static_cast<std::string>(x.repr()) << ", "
+        << static_cast<std::string>(y.repr()) << ", "
+        << static_cast<std::string>(z.repr());
     str << ")";
 
     return str.str();
@@ -192,8 +194,10 @@ PyObject * VectorPy::sequence_item (PyObject *self, Py_ssize_t index)
         return nullptr;
     }
 
+    unsigned short pos = index % 3;
+
     Base::Vector3d a = static_cast<VectorPy*>(self)->value();
-    return Py_BuildValue("d", a[index]);
+    return Py_BuildValue("d", a[pos]);
 }
 
 int VectorPy::sequence_ass_item(PyObject *self, Py_ssize_t index, PyObject *value)
@@ -207,9 +211,11 @@ int VectorPy::sequence_ass_item(PyObject *self, Py_ssize_t index, PyObject *valu
         return -1;
     }
 
+    unsigned short pos = index % 3;
+
     if (PyNumber_Check(value)) {
         VectorPy::PointerType ptr = static_cast<VectorPy*>(self)->getVectorPtr();
-        (*ptr)[index] = PyFloat_AsDouble(value);
+        (*ptr)[pos] = PyFloat_AsDouble(value);
     }
     else {
         PyErr_SetString(PyExc_ValueError, "value must be float");
@@ -255,11 +261,11 @@ PyObject * VectorPy::mapping_subscript(PyObject *self, PyObject *item)
         }
         else if (PyObject_TypeCheck(self, &(VectorPy::Type))) {
             Base::Vector3d v = static_cast<VectorPy*>(self) ->value();
-            Py::Tuple xyz(slicelength);
+            Py::Tuple xyz(static_cast<size_t>(slicelength));
 
-            for (cur = start, i = 0; i < slicelength;
-                 cur += step, i++) {
-                xyz.setItem(i, Py::Float(v[cur]));
+            for (cur = start, i = 0; i < slicelength; cur += step, i++) {
+                unsigned short pos = cur % 3;
+                xyz.setItem(static_cast<Py::sequence_index_type>(i), Py::Float(v[pos]));
             }
 
             return Py::new_reference_to(xyz);
@@ -622,7 +628,7 @@ void  VectorPy::setLength(Py::Float arg)
         throw Py::RuntimeError(std::string("Cannot set length of null vector"));
     }
 
-    double val = (double)arg/len;
+    double val = static_cast<double>(arg)/len;
     ptr->x *= val;
     ptr->y *= val;
     ptr->z *= val;
@@ -637,7 +643,7 @@ Py::Float VectorPy::getx() const
 void  VectorPy::setx(Py::Float arg)
 {
     VectorPy::PointerType ptr = reinterpret_cast<VectorPy::PointerType>(_pcTwinPointer);
-    ptr->x = (double)arg;
+    ptr->x = static_cast<double>(arg);
 }
 
 Py::Float VectorPy::gety() const
@@ -649,7 +655,7 @@ Py::Float VectorPy::gety() const
 void  VectorPy::sety(Py::Float arg)
 {
     VectorPy::PointerType ptr = reinterpret_cast<VectorPy::PointerType>(_pcTwinPointer);
-    ptr->y = (double)arg;
+    ptr->y = static_cast<double>(arg);
 }
 
 Py::Float VectorPy::getz() const
@@ -661,7 +667,7 @@ Py::Float VectorPy::getz() const
 void  VectorPy::setz(Py::Float arg)
 {
     VectorPy::PointerType ptr = reinterpret_cast<VectorPy::PointerType>(_pcTwinPointer);
-    ptr->z = (double)arg;
+    ptr->z = static_cast<double>(arg);
 }
 
 PyObject *VectorPy::getCustomAttributes(const char* /*attr*/) const
@@ -693,7 +699,7 @@ PyObject * VectorPy::number_divide_handler (PyObject* self, PyObject* other)
 
         Base::Vector3d vec = static_cast<VectorPy*>(self) ->value();
         double div = PyFloat_AsDouble(other);
-        if (div == 0) {
+        if (div == 0.0) {
             PyErr_Format(PyExc_ZeroDivisionError, "'%s' division by zero",
                          Py_TYPE(self)->tp_name);
             return nullptr;
diff --git a/src/Mod/Mesh/App/Core/Visitor.h b/src/Mod/Mesh/App/Core/Visitor.h
index f410d9a56f..fc793db5a7 100644
--- a/src/Mod/Mesh/App/Core/Visitor.h
+++ b/src/Mod/Mesh/App/Core/Visitor.h
@@ -24,7 +24,8 @@
 #ifndef VISITOR_H
 #define VISITOR_H
 
-#include "Definitions.h"
+#include <vector>
+#include <Base/Vector3D.h>
 #include <Mod/Mesh/MeshGlobal.h>
 
 namespace MeshCore {
@@ -32,6 +33,7 @@ namespace MeshCore {
 class MeshFacet;
 class MeshKernel;
 class MeshFacetVisitor;
+class MeshPoint;
 class PlaneFit;
 
 /**