STYLE: Prefer = delete to explicitly trivial implementations

This check replaces undefined special member functions with
= delete;. The explicitly deleted function declarations enable more
opportunities in optimization, because the compiler might treat
explicitly delted functions as noops.

Additionally, the C++11 use of = delete more clearly expreses the
intent for the special member functions.

Modules/Bridge/VtkGlue/include/vtkCaptureScreen.h

@@ -52,9 +52,9 @@ class vtkCaptureScreen
   }
 
 private:
-  vtkCaptureScreen(const vtkCaptureScreen &);
+  vtkCaptureScreen(const vtkCaptureScreen &) = delete;
   void
-  operator=(const vtkCaptureScreen &);
+  operator=(const vtkCaptureScreen &) = delete;
 
   vtkRenderWindow * m_Renderer{ nullptr };
 

Modules/Core/GPUCommon/include/itkGPUImageOps.h

@@ -43,8 +43,8 @@ class GPUImageOps
   itkGetOpenCLSourceFromKernelMacro(GPUImageOpsKernel);
 
 private:
-  GPUImageOps();
-  virtual ~GPUImageOps();
+  GPUImageOps() = delete;
+  virtual ~GPUImageOps() = delete;
 };
 
 

Modules/Nonunit/Review/include/itkConstrainedRegionBasedLevelSetFunctionSharedData.h

@@ -182,13 +182,9 @@ class ConstrainedRegionBasedLevelSetFunctionSharedData
   ~ConstrainedRegionBasedLevelSetFunctionSharedData() override = default;
 
 private:
-  ConstrainedRegionBasedLevelSetFunctionSharedData(const Self &); // purposely
-                                                                  // not
-                                                                  // implemented
+  ConstrainedRegionBasedLevelSetFunctionSharedData(const Self &) = delete;
   void
-  operator=(const Self &); // purposely
-                           // not
-                           // implemented
+  operator=(const Self &) = delete;
 };
 } // end namespace itk
 

Modules/Nonunit/Review/include/itkUnconstrainedRegionBasedLevelSetFunctionSharedData.h

@@ -141,13 +141,9 @@ class UnconstrainedRegionBasedLevelSetFunctionSharedData
   ~UnconstrainedRegionBasedLevelSetFunctionSharedData() override = default;
 
 private:
-  UnconstrainedRegionBasedLevelSetFunctionSharedData(const Self &); // purposely
-                                                                    // not
-                                                                    // implemented
+  UnconstrainedRegionBasedLevelSetFunctionSharedData(const Self &) = delete;
   void
-  operator=(const Self &); // purposely
-                           // not
-                           // implemented
+  operator=(const Self &) = delete;
 };
 } // end namespace itk
 

Modules/Numerics/FEM/include/itkFEMLinearSystemWrapper.h

@@ -532,11 +532,11 @@ class ITKFEM_EXPORT LinearSystemWrapper : public Solution
                                         unsigned int  matrixIndex = 0);
 
   /** Copy constructor is not allowed. */
-  LinearSystemWrapper(const LinearSystemWrapper &);
+  LinearSystemWrapper(const LinearSystemWrapper &) = delete;
 
   /** Asignment operator is not allowed. */
   const LinearSystemWrapper &
-  operator=(const LinearSystemWrapper &);
+  operator=(const LinearSystemWrapper &) = delete;
 };
 
 class ITK_ABI_EXPORT FEMExceptionLinearSystem : public FEMException