STYLE: Replace T var{ NumericTraits<T>::ZeroValue() } with T var{}

Replaced brace-initialization by `NumericTraits<T>::ZeroValue()` with empty `{}`
initializers. Did so by Replace in Files, using regular expressions:

    Find what: (\w.+)( .+){ NumericTraits<\1>::ZeroValue\(\) };
    Replace with:  $1$2{};

Follow-up to pull request #3958
commit 42b0bfc
"STYLE: Replace `T var = NumericTraits<T>::ZeroValue()` with `T var{}`"

Modules/Core/Common/include/itkAnnulusOperator.h

@@ -245,9 +245,9 @@ class ITK_TEMPLATE_EXPORT AnnulusOperator : public NeighborhoodOperator<TPixel,
   double      m_Thickness{ 1.0 };
   bool        m_Normalize{ false };
   bool        m_BrightCenter{ false };
-  PixelType   m_InteriorValue{ NumericTraits<PixelType>::ZeroValue() };
+  PixelType   m_InteriorValue{};
   PixelType   m_AnnulusValue{ NumericTraits<PixelType>::OneValue() };
-  PixelType   m_ExteriorValue{ NumericTraits<PixelType>::ZeroValue() };
+  PixelType   m_ExteriorValue{};
   SpacingType m_Spacing{ MakeFilled<SpacingType>(1.0) };
 };
 } // namespace itk

Modules/Filtering/DistanceMap/include/itkDirectedHausdorffDistanceImageFilter.h

@@ -181,13 +181,13 @@ class ITK_TEMPLATE_EXPORT DirectedHausdorffDistanceImageFilter : public ImageToI
 
   DistanceMapPointer m_DistanceMap{ nullptr };
 
-  RealType       m_MaxDistance{ NumericTraits<RealType>::ZeroValue() };
+  RealType       m_MaxDistance{};
   IdentifierType m_PixelCount{};
 
   CompensatedSummationType m_Sum{};
 
-  RealType m_DirectedHausdorffDistance{ NumericTraits<RealType>::ZeroValue() };
-  RealType m_AverageHausdorffDistance{ NumericTraits<RealType>::ZeroValue() };
+  RealType m_DirectedHausdorffDistance{};
+  RealType m_AverageHausdorffDistance{};
   bool     m_UseImageSpacing{ true };
 
   std::mutex m_Mutex{};

Modules/Filtering/ImageIntensity/include/itkMaskImageFilter.h

@@ -105,7 +105,7 @@ class MaskInput
     return VariableLengthVector<TValue>(0);
   }
   TOutput m_OutsideValue{ DefaultOutsideValue(static_cast<TOutput *>(nullptr)) };
-  TMask   m_MaskingValue{ NumericTraits<TMask>::ZeroValue() };
+  TMask   m_MaskingValue{};
 };
 } // namespace Functor
 

Modules/Filtering/ImageIntensity/include/itkMaskNegatedImageFilter.h

@@ -105,7 +105,7 @@ class MaskNegatedInput
     return VariableLengthVector<TValue>(0);
   }
   TOutput m_OutsideValue{ DefaultOutsideValue(static_cast<TOutput *>(nullptr)) };
-  TMask   m_MaskingValue{ NumericTraits<TMask>::ZeroValue() };
+  TMask   m_MaskingValue{};
 };
 } // namespace Functor
 

Modules/Filtering/ImageIntensity/include/itkShiftScaleImageFilter.h

@@ -117,7 +117,7 @@ class ITK_TEMPLATE_EXPORT ShiftScaleImageFilter : public ImageToImageFilter<TInp
   DynamicThreadedGenerateData(const OutputImageRegionType &) override;
 
 private:
-  RealType m_Shift{ NumericTraits<RealType>::ZeroValue() };
+  RealType m_Shift{};
   RealType m_Scale{ NumericTraits<RealType>::OneValue() };
 
   SizeValueType m_UnderflowCount{ 0 };

Modules/Filtering/LabelMap/include/itkStatisticsLabelMapFilter.h

@@ -156,8 +156,8 @@ class ITK_TEMPLATE_EXPORT StatisticsLabelMapFilter
   PrintSelf(std::ostream & os, Indent indent) const override;
 
 private:
-  FeatureImagePixelType m_Minimum{ NumericTraits<FeatureImagePixelType>::ZeroValue() };
-  FeatureImagePixelType m_Maximum{ NumericTraits<FeatureImagePixelType>::ZeroValue() };
+  FeatureImagePixelType m_Minimum{};
+  FeatureImagePixelType m_Maximum{};
   unsigned int          m_NumberOfBins{ GetDefaultNumberOfBins() };
   bool                  m_ComputeHistogram{ true };
 }; // end of class