COMP: Replace itkStaticConstMacro with constexpr in 1D FFT classes

Resolves CTest compiler warnings at https://open.cdash.org/viewBuildError.php?buildid=7507611

Author: tbirdso

Modules/Filtering/FFT/include/itkComplexToComplex1DFFTImageFilter.h

@@ -54,7 +54,8 @@ class ITK_TEMPLATE_EXPORT ComplexToComplex1DFFTImageFilter : public ImageToImage
   using Pointer = SmartPointer<Self>;
   using ConstPointer = SmartPointer<const Self>;
 
-  itkStaticConstMacro(ImageDimension, unsigned int, InputImageType::ImageDimension);
+  /** Dimension of the underlying image. */
+  static constexpr unsigned int ImageDimension = InputImageType::ImageDimension;
 
   itkTypeMacro(ComplexToComplex1DFFTImageFilter, ImageToImageFilter);
 

Modules/Filtering/FFT/include/itkForward1DFFTImageFilter.h

@@ -48,7 +48,8 @@ class ITK_TEMPLATE_EXPORT Forward1DFFTImageFilter : public ImageToImageFilter<TI
   using Pointer = SmartPointer<Self>;
   using ConstPointer = SmartPointer<const Self>;
 
-  itkStaticConstMacro(ImageDimension, unsigned int, InputImageType::ImageDimension);
+  /** Dimension of the underlying image. */
+  static constexpr unsigned int ImageDimension = InputImageType::ImageDimension;
 
   itkTypeMacro(Forward1DFFTImageFilter, ImageToImageFilter);
 

Modules/Filtering/FFT/include/itkInverse1DFFTImageFilter.h

@@ -49,7 +49,8 @@ class ITK_TEMPLATE_EXPORT Inverse1DFFTImageFilter : public ImageToImageFilter<TI
   using Pointer = SmartPointer<Self>;
   using ConstPointer = SmartPointer<const Self>;
 
-  itkStaticConstMacro(ImageDimension, unsigned int, InputImageType::ImageDimension);
+  /** Dimension of the underlying image. */
+  static constexpr unsigned int ImageDimension = InputImageType::ImageDimension;
 
   itkTypeMacro(Inverse1DFFTImageFilter, ImageToImageFilter);