STYLE: Prefer = default to explicitly trivial implementations

This check replaces default bodies of special member functions with
= default;. The explicitly defaulted function declarations enable more
opportunities in optimization, because the compiler might treat
explicitly defaulted functions as trivial.

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

Author: hjmjohnson

Modules/Filtering/FFT/include/itkComplexToComplex1DFFTImageFilter.hxx

@@ -25,8 +25,7 @@
 namespace itk
 {
 template <typename TInputImage, typename TOutputImage>
-ComplexToComplex1DFFTImageFilter<TInputImage, TOutputImage>::ComplexToComplex1DFFTImageFilter()
-{}
+ComplexToComplex1DFFTImageFilter<TInputImage, TOutputImage>::ComplexToComplex1DFFTImageFilter() = default;
 
 
 template <typename TInputImage, typename TOutputImage>

Modules/Filtering/FFT/include/itkFFTWCommonExtended.h

@@ -46,8 +46,8 @@ class ComplexToComplexProxy
 {
   // empty -- only double and float specializations work
 protected:
-  ComplexToComplexProxy(){};
-  ~ComplexToComplexProxy(){};
+  ComplexToComplexProxy() = default;
+  ~ComplexToComplexProxy() = default;
 };
 
 #if defined(ITK_USE_FFTWF)

Modules/Filtering/FFT/include/itkForward1DFFTImageFilter.hxx

@@ -26,7 +26,7 @@ namespace itk
 template <typename TInputImage, typename TOutputImage>
 Forward1DFFTImageFilter<TInputImage, TOutputImage>::Forward1DFFTImageFilter()
 
-{}
+  = default;
 
 
 template <typename TInputImage, typename TOutputImage>

Modules/Filtering/FFT/include/itkInverse1DFFTImageFilter.hxx

@@ -27,7 +27,7 @@ namespace itk
 template <typename TInputImage, typename TOutputImage>
 Inverse1DFFTImageFilter<TInputImage, TOutputImage>::Inverse1DFFTImageFilter()
 
-{}
+  = default;
 
 
 template <typename TInputImage, typename TOutputImage>