Prefer cxx modern names directly

.github/workflows/itk_dict.txt

@@ -652,6 +652,7 @@ mv
 myhistogram
 myreferenceimage
 mx
+natively
 nbOfDirections
 nbOfPixels
 ncodewords

CMake/ITKConfig.cmake.in

@@ -26,9 +26,6 @@ set(ITK_VERSION_MAJOR "@ITK_VERSION_MAJOR@")
 set(ITK_VERSION_MINOR "@ITK_VERSION_MINOR@")
 set(ITK_VERSION_PATCH "@ITK_VERSION_PATCH@")
 
-# If ITK was built with version 4 compatibility features.
-set(ITKV4_COMPATIBILITY "@ITKV4_COMPATIBILITY@")
-
 # Remove all legacy code completely.
 set(ITK_LEGACY_REMOVE "@ITK_LEGACY_REMOVE@")
 

CMakeLists.txt

@@ -325,20 +325,16 @@ cmake_dependent_option(
   OFF
   "NOT ITK_LEGACY_REMOVE"
   OFF)
-# The disabling of legacy code, and the ITKv4 compatibility option can not both be
-# requested. If removal of legacy code is requested, then ITKV4_COMPATIBILITY must
-# be off.
-cmake_dependent_option(
-  ITKV4_COMPATIBILITY
-  "Enable LEGACY compatibility with ITK4.x when possible."
-  OFF
-  "NOT ITK_LEGACY_REMOVE"
-  OFF)
+
 mark_as_advanced(
   ITK_LEGACY_SILENT
   ITK_LEGACY_REMOVE
   ITK_FUTURE_LEGACY_REMOVE
-  ITKV4_COMPATIBILITY)
+  )
+
+if(ITKV4_COMPATIBILITY)
+  message(FATAL_ERROR "ITKV4_COMPATIBILITY is removed starting in ITK version 4.0, this option is no longer valid.")
+endif()
 
 if(ITKV3_COMPATIBILITY)
   message(FATAL_ERROR "ITKV3_COMPATIBILITY is removed starting in ITK version 5.0, this option is no longer valid.")

Documentation/docs/migration_guides/itk_6_migration_guide.md

@@ -21,3 +21,19 @@ re-flagged as `ITK_LEGACY_REMOVE`. There have been some other
 deprecations and API changes. The new behavior is activated by setting
 `ITK_LEGACY_REMOVE` to `ON`. By default, compatibility with v5 is retained
 (`ITK_LEGACY_REMOVE=OFF`).
+
+Remove support for ITKv4 interfaces
+-----------------------------------
+
+ITKV4_COMPATIBILITY is no longer a supported option.
+
+Require modern C++ language feature use
+---------------------------------------
+
+Many backward compatible/ forward enabling compiler features are now required to be used.
+
+* `ITKv5_CONST` must be replaced with `const`
+* `ITK_ITERATOR_VIRTUAL` must be replaced with `virtual`
+* `ITK_ITERATOR_OVERRIDE` must be replaced with `override`
+* `ITK_ITERATOR_FINAL` must be replaced with `final`
+* `ITK_DELETE_FUNCTION` must be replaced with `delete`

Modules/Compatibility/Deprecated/include/itkImageTransformer.hxx

@@ -323,20 +323,6 @@ ImageTransformer<TInputImage>::ThreaderCallback(void * arg)
   if (threadId < total)
   {
     str->Filter->ThreadedGenerateData(splitRegion, threadId);
-#if defined(ITKV4_COMPATIBILITY)
-    if (str->Filter->GetAbortGenerateData())
-    {
-      std::string    msg;
-      ProcessAborted e(__FILE__, __LINE__);
-      msg += "Object " + std::string(str->Filter->GetNameOfClass()) + ": AbortGenerateData was set!";
-      e.SetDescription(msg);
-      throw e;
-    }
-    else if (str->Filter->GetProgress() == 0.0f) // progress was not set after at least the first chunk finished
-    {
-      str->Filter->UpdateProgress(static_cast<float>(threadId + 1) / total); // this will be the only progress update
-    }
-#endif
   }
   // else
   //   {

Modules/Compatibility/Deprecated/itk-module.cmake

@@ -2,9 +2,6 @@ set(DOCUMENTATION "This is a collection of classes that are intended to be
 removed from the toolkit.")
 
 set(ITKDeprecatedOnByDefault EXCLUDE_FROM_DEFAULT)
-if(ITKV4_COMPATIBILITY)
-  set(ITKDeprecatedOnByDefault "")
-endif()
 
 itk_module(
   ITKDeprecated

Modules/Core/Common/include/itkArray.h

@@ -81,21 +81,12 @@ class ITK_TEMPLATE_EXPORT Array : public vnl_vector<TValue>
    * memory when this object is destroyed. */
   Array(ValueType * datain, SizeValueType sz, bool LetArrayManageMemory = false);
 
-#if defined(ITK_LEGACY_REMOVE)
   /** Constructor that initializes array with contents from a user supplied
    * const buffer. The pointer to the buffer and the length is specified. By default,
    * the array does a deep copy of the const pointer data, so the array class also
    * manages memory. */
   Array(const ValueType * datain, SizeValueType sz);
 
-#else // defined ( ITK_LEGACY_REMOVE )
-  /** Constructor that initializes array with contents from a user supplied
-   * buffer. The pointer to the buffer and the length is specified. The array
-   * does a deep copy of the const pointer data, so the array class also
-   * manages memory. The 3rd argument is only for backward compatibility. */
-  Array(const ValueType * datain, SizeValueType sz, bool LetArrayManageMemory = false);
-#endif
-
   /** Constructor to initialize an array from another of any data type */
   template <typename TArrayValue>
   Array(const Array<TArrayValue> & r)
@@ -187,14 +178,6 @@ class ITK_TEMPLATE_EXPORT Array : public vnl_vector<TValue>
    * means that subclasses cannot allocate memory. */
   ~Array() override;
 
-#if !defined(ITK_LEGACY_REMOVE)
-  void
-  swap(Array & other)
-  {
-    this->Swap(other);
-  }
-#endif
-
   void
   Swap(Array & other)
   {

Modules/Core/Common/include/itkArray.hxx

@@ -58,25 +58,13 @@ Array<TValue>::Array(ValueType * datain, SizeValueType sz, bool LetArrayManageMe
   vnl_vector<TValue>::num_elmts = sz;
 }
 
-#if defined(ITK_LEGACY_REMOVE)
 template <typename TValue>
 Array<TValue>::Array(const ValueType * datain, SizeValueType sz)
   : vnl_vector<TValue>(datain, sz)
 // The vnl vector copy constructor creates new memory
 // no matter the setting of let array manage memory of rhs
 {}
 
-#else // defined ( ITK_LEGACY_REMOVE )
-template <typename TValue>
-Array<TValue>::Array(const ValueType * datain, SizeValueType sz, bool /* LetArrayManageMemory */)
-  : /* NOTE: The 3rd argument "LetArrayManageMemory, was never valid to use, but is
-     * preserved to maintain backwards compatibility*/
-  vnl_vector<TValue>(datain, sz)
-// The vnl vector copy constructor creates new memory
-// no matter the setting of let array manage memory of rhs
-{}
-#endif
-
 template <typename TValue>
 Array<TValue>::~Array()
 {

Modules/Core/Common/include/itkBSplineInterpolationWeightFunction.h

@@ -104,14 +104,6 @@ class ITK_TEMPLATE_EXPORT BSplineInterpolationWeightFunction
   virtual void
   Evaluate(const ContinuousIndexType & index, WeightsType & weights, IndexType & startIndex) const;
 
-#if !defined(ITK_LEGACY_REMOVE)
-  /** Get support region size. */
-  itkLegacyMacro(SizeType GetSupportSize() const) { return Self::SupportSize; };
-
-  /** Get number of weights. */
-  itkLegacyMacro(unsigned int GetNumberOfWeights() const) { return Self::NumberOfWeights; }
-#endif
-
 protected:
   BSplineInterpolationWeightFunction() = default;
   ~BSplineInterpolationWeightFunction() override = default;

Modules/Core/Common/include/itkBoundingBox.h

@@ -198,12 +198,9 @@ class ITK_TEMPLATE_EXPORT BoundingBox : public Object
 
 private:
   PointsContainerConstPointer m_PointsContainer{};
-#if !defined(ITK_LEGACY_REMOVE)
-  PointsContainerPointer m_CornersContainer{ PointsContainer::New() };
-#endif
-  mutable BoundsArrayType m_Bounds{};
-  mutable TimeStamp       m_BoundsMTime{}; // The last time the bounds
-                                           // were computed.
+  mutable BoundsArrayType     m_Bounds{};
+  mutable TimeStamp           m_BoundsMTime{}; // The last time the bounds
+                                               // were computed.
 };
 } // end namespace itk
 

Modules/Core/Common/include/itkBoundingBox.hxx

@@ -108,26 +108,6 @@ BoundingBox<TPointIdentifier, VPointDimension, TCoordRep, TPointsContainer>::Com
   return result;
 }
 
-#if !defined(ITK_LEGACY_REMOVE)
-/** Compute and get the corners of the bounding box */
-template <typename TPointIdentifier, unsigned int VPointDimension, typename TCoordRep, typename TPointsContainer>
-auto
-BoundingBox<TPointIdentifier, VPointDimension, TCoordRep, TPointsContainer>::GetCorners() -> const PointsContainer *
-{
-  m_CornersContainer->clear();
-  m_CornersContainer->Reserve(NumberOfCorners);
-
-  SizeValueType index = 0;
-  for (const PointType & pnt : this->ComputeCorners())
-  {
-    m_CornersContainer->SetElement(index++, pnt);
-  }
-
-  return m_CornersContainer.GetPointer();
-}
-#endif
-
-
 template <typename TPointIdentifier, unsigned int VPointDimension, typename TCoordRep, typename TPointsContainer>
 bool
 BoundingBox<TPointIdentifier, VPointDimension, TCoordRep, TPointsContainer>::ComputeBoundingBox() const
@@ -344,23 +324,6 @@ BoundingBox<TPointIdentifier, VPointDimension, TCoordRep, TPointsContainer>::Dee
   // Connect the same points container into the clone
   clone->SetPoints(this->m_PointsContainer);
 
-#if !defined(ITK_LEGACY_REMOVE)
-  // Copy the corners into the clone.
-  clone->m_CornersContainer->clear();
-
-  PointsContainerConstIterator itr = this->m_CornersContainer->Begin();
-  PointsContainerConstIterator end = this->m_CornersContainer->End();
-
-  clone->m_CornersContainer->Reserve(this->m_CornersContainer->Size());
-  PointsContainerIterator dest = clone->m_CornersContainer->Begin();
-
-  while (itr != end)
-  {
-    dest.Value() = itr.Value();
-    ++itr;
-  }
-#endif
-
   // Copy the bounds into the clone
   for (unsigned int i = 0; i < 2 * PointDimension; ++i)
   {

Modules/Core/Common/include/itkCellInterface.h

@@ -472,22 +472,6 @@ class ITK_TEMPLATE_EXPORT CellInterface
   /** Get the geometric position of a point. */
   //  bool GetPointPosition(PointsContainer*, int localId, Point*)=0;
 
-#if !defined(ITK_LEGACY_REMOVE)
-  /** Expose old names for backwards compatibility*/
-  static constexpr CommonEnums::CellGeometry VERTEX_CELL = CommonEnums::CellGeometry::VERTEX_CELL;
-  static constexpr CommonEnums::CellGeometry LINE_CELL = CommonEnums::CellGeometry::LINE_CELL;
-  static constexpr CommonEnums::CellGeometry TRIANGLE_CELL = CommonEnums::CellGeometry::TRIANGLE_CELL;
-  static constexpr CommonEnums::CellGeometry QUADRILATERAL_CELL = CommonEnums::CellGeometry::QUADRILATERAL_CELL;
-  static constexpr CommonEnums::CellGeometry POLYGON_CELL = CommonEnums::CellGeometry::POLYGON_CELL;
-  static constexpr CommonEnums::CellGeometry TETRAHEDRON_CELL = CommonEnums::CellGeometry::TETRAHEDRON_CELL;
-  static constexpr CommonEnums::CellGeometry HEXAHEDRON_CELL = CommonEnums::CellGeometry::HEXAHEDRON_CELL;
-  static constexpr CommonEnums::CellGeometry QUADRATIC_EDGE_CELL = CommonEnums::CellGeometry::QUADRATIC_EDGE_CELL;
-  static constexpr CommonEnums::CellGeometry QUADRATIC_TRIANGLE_CELL =
-    CommonEnums::CellGeometry::QUADRATIC_TRIANGLE_CELL;
-  static constexpr CommonEnums::CellGeometry LAST_ITK_CELL = CommonEnums::CellGeometry::LAST_ITK_CELL;
-  static constexpr CommonEnums::CellGeometry MAX_ITK_CELLS = CommonEnums::CellGeometry::MAX_ITK_CELLS;
-#endif
-
 protected:
   /** Store the set of cells using this boundary. */
   UsingCellsContainer m_UsingCells{};

Modules/Core/Common/include/itkCommonEnums.h

@@ -161,15 +161,6 @@ using IOFileModeEnum = CommonEnums::IOFileMode;
 using IOByteOrderEnum = CommonEnums::IOByteOrder;
 using CellGeometryEnum = CommonEnums::CellGeometry;
 
-#if !defined(ITK_LEGACY_REMOVE)
-/** Expose old names for backwards compatibility*/
-using IOPixelType = CommonEnums::IOPixel;
-using IOComponentType = CommonEnums::IOComponent;
-using IOFileType = CommonEnums::IOFile;
-using IOFileModeType = CommonEnums::IOFileMode;
-using IOByteOrderType = CommonEnums::IOByteOrder;
-using CellGeometryType = CommonEnums::CellGeometry;
-#endif
 // Define how to print enumeration
 extern ITKCommon_EXPORT std::ostream &
                         operator<<(std::ostream & out, IOPixelEnum value);