STYLE: Use C++17 nested namespace syntax

Modules/Core/Common/include/itkBinaryOperationConcept.h

@@ -22,11 +22,8 @@
 #include "itkPromoteType.h"
 
 /// \cond HIDE_META_PROGRAMMING
-namespace itk
-{
-namespace Details
-{
-namespace op
+
+namespace itk::Details::op
 {
 /** Root Binary Operation Concept.
  * All binary operations are expected to inherit from this type.
@@ -99,9 +96,7 @@ struct Div : BinaryOperationConcept
   }
 };
 
-} // namespace op
-} // namespace Details
-} // namespace itk
+} // namespace itk::Details::op
 /// \endcond
 
 #endif // itkBinaryOperationConcept_h

Modules/Core/Common/include/itkConceptChecking.h

@@ -107,11 +107,10 @@
 
 #endif
 
-namespace itk
-{
+
 /** All concept class definitions are contained in the "itk::Concept"
     namespace. */
-namespace Concept
+namespace itk::Concept
 {
 
 /**
@@ -978,7 +977,6 @@ struct IsFixedPoint
 
   itkConceptConstraintsMacro();
 };
-} // end namespace Concept
-} // end namespace itk
+} // namespace itk::Concept
 
 #endif

Modules/Core/Common/include/itkExtractImageFilterRegionCopier.h

@@ -30,9 +30,7 @@
 
 #include "itkImageToImageFilterDetail.h"
 
-namespace itk
-{
-namespace ImageToImageFilterDetail
+namespace itk::ImageToImageFilterDetail
 {
 /**
  *  Call the base class version: ImageToImageFilterDefaultCopyRegion
@@ -156,7 +154,6 @@ class ITK_TEMPLATE_EXPORT ExtractImageFilterRegionCopier : public ImageRegionCop
     ImageRegionCopier<T1, T2>::operator()(destRegion, srcRegion);
   }
 };
-} // end namespace ImageToImageFilterDetail
-} // end namespace itk
+} // namespace itk::ImageToImageFilterDetail
 
 #endif

Modules/Core/Common/include/itkImageToImageFilterDetail.h

@@ -31,8 +31,7 @@
 #include "itkImageRegion.h"
 #include "itkSmartPointer.h"
 
-namespace itk
-{
+
 /** ImageToImageFilterDetail namespace to house implementations of
  * functions that are dependent on dimension. These functions are
  * overloaded based on type unique for each different dimension.
@@ -41,7 +40,7 @@ namespace itk
  * ImageToImageFilter would force the instantiation of all versions of
  * these overloaded functions.
  */
-namespace ImageToImageFilterDetail
+namespace itk::ImageToImageFilterDetail
 {
 
 /** \struct  DispatchBase
@@ -448,7 +447,6 @@ class ImageInformationCopier
 };
 
 
-} // end of namespace ImageToImageFilterDetail
-} // end namespace itk
+} // namespace itk::ImageToImageFilterDetail
 
 #endif

Modules/Core/Common/include/itkIsNumber.h

@@ -22,10 +22,9 @@
 #include "itkMetaProgrammingLibrary.h"
 #include "itkIntTypes.h"
 
-namespace itk
-{
+
 /// \cond HIDE_META_PROGRAMMING
-namespace mpl
+namespace itk::mpl
 {
 /** Tells whether a type is a number.
  * \c TrueType for all kinds of numbers from \c short to `long long`,
@@ -79,8 +78,7 @@ struct IsNumber<long double> : TrueType
 {};
 /// \endcond
 
-} // end namespace mpl
+} // namespace itk::mpl
 /// \endcond
-} // end namespace itk
 
 #endif // itkIsNumber_h

Modules/Core/Common/include/itkLexicographicCompare.h

@@ -23,15 +23,13 @@
 #include <iterator> // For std::begin, std::end, and reverse_iterator.
 #include "itkMacro.h"
 
-namespace itk
-{
 
 /*
 The  Functor was only used in one spot in the
 LevelSet class,  It does not exist in Slicer, BRAINSTools, Remote modules,
 ANTs, or any other project that I could find.
 */
-namespace Functor
+namespace itk::Functor
 {
 /** \class LexicographicCompare
  * \brief Order Index instances lexicographically.
@@ -84,7 +82,6 @@ class CoLexicographicCompare
 };
 
 
-} // end namespace Functor
-} // end namespace itk
+} // namespace itk::Functor
 
 #endif

Modules/Core/Common/include/itkMath.h

@@ -41,10 +41,7 @@
  */
 #include <vxl_version.h>
 
-
-namespace itk
-{
-namespace Math
+namespace itk::Math
 {
 // These constants originate from VXL's vnl_math.h. They have been
 // moved here to improve visibility, and to ensure that the constants
@@ -881,7 +878,6 @@ abs(unsigned long long x)
 
 using std::abs;
 
-} // end namespace Math
-} // end namespace itk
+} // namespace itk::Math
 
 #endif // end of itkMath.h

Modules/Core/Common/include/itkMathDetail.h

@@ -74,9 +74,8 @@
 
 namespace itk
 {
-namespace Math
-{
-namespace Detail
+
+namespace Math::Detail
 {
 // The functions defined in this namespace are not meant to be used directly
 // and thus do not adhere to the standard backward-compatibility
@@ -515,8 +514,8 @@ union FloatIEEE
   }
 };
 
-} // end namespace Detail
-} // end namespace Math
+} // namespace Math::Detail
+// end namespace Math
 
 // move to itkConceptChecking?
 namespace Concept

Modules/Core/Common/include/itkMersenneTwisterRandomVariateGenerator.h

@@ -31,9 +31,7 @@
 #include <ctime>
 #include <limits>
 
-namespace itk
-{
-namespace Statistics
+namespace itk::Statistics
 {
 /** \class MersenneTwisterRandomVariateGenerator
  * \brief MersenneTwisterRandom random variate generator
@@ -425,7 +423,6 @@ MersenneTwisterRandomVariateGenerator::GetUniformVariate(const double a, const d
 //      - Fixed out-of-range number generation on 64-bit machines
 //      - Improved portability by substituting literal constants for long enum's
 //      - Changed license from GNU LGPL to BSD
-} // end namespace Statistics
-} // end namespace itk
+} // namespace itk::Statistics
 
 #endif

Modules/Core/Common/include/itkMetaDataObjectDetail.h

@@ -23,11 +23,9 @@
 #include <utility>
 #include <iosfwd>
 
-namespace itk
-{
 
 // Implementation details for MetaDataObject meta programming
-namespace MetaDataObjectDetail
+namespace itk::MetaDataObjectDetail
 {
 template <class T, class = void>
 struct has_Print : std::false_type
@@ -45,7 +43,7 @@ template <class T>
 struct has_output_operator<T, std::void_t<decltype(std::declval<std::ostream &>() << std::declval<T>())>>
   : std::true_type
 {};
-} // namespace MetaDataObjectDetail
-} // namespace itk
+} // namespace itk::MetaDataObjectDetail
+
 
 #endif

Modules/Core/Common/include/itkNeighborhoodAlgorithm.h

@@ -23,9 +23,7 @@
 #include "itkNeighborhoodOperator.h"
 #include "itkNeighborhoodIterator.h"
 
-namespace itk
-{
-namespace NeighborhoodAlgorithm
+namespace itk::NeighborhoodAlgorithm
 {
 /** \class ImageBoundaryFacesCalculator
  *   \brief Splits an image into a main region and several "face" regions
@@ -138,8 +136,7 @@ struct CalculateOutputWrapOffsetModifiers
   OffsetType
   operator()(TImage *, TImage *) const;
 };
-} // end namespace NeighborhoodAlgorithm
-} // end namespace itk
+} // namespace itk::NeighborhoodAlgorithm
 
 #ifndef ITK_MANUAL_INSTANTIATION
 #  include "itkNeighborhoodAlgorithm.hxx"

Modules/Core/Common/include/itkNeighborhoodAlgorithm.hxx

@@ -22,9 +22,7 @@
 #include "itkConstSliceIterator.h"
 #include <algorithm> // For min.
 
-namespace itk
-{
-namespace NeighborhoodAlgorithm
+namespace itk::NeighborhoodAlgorithm
 {
 template <typename TImage>
 auto
@@ -188,7 +186,6 @@ CalculateOutputWrapOffsetModifiers<TImage>::operator()(TImage * input, TImage *
   }
   return ans;
 }
-} // end namespace NeighborhoodAlgorithm
-} // end namespace itk
+} // namespace itk::NeighborhoodAlgorithm
 
 #endif

Modules/Core/Common/include/itkPrintHelper.h

@@ -33,10 +33,7 @@
 #  undef ITK_CASTXML_GCC_VECTOR_WORKAROUND
 #endif
 
-namespace itk
-{
-
-namespace print_helper
+namespace itk::print_helper
 {
 
 template <typename T>
@@ -53,7 +50,6 @@ operator<<(std::ostream & os, const std::vector<T> & v)
   return os << v.back() << ')';
 }
 
-} // end namespace print_helper
-} // end namespace itk
+} // namespace itk::print_helper
 
 #endif // itkPrintHelper_h

Modules/Core/Common/include/itkPromoteType.h

@@ -21,11 +21,10 @@
 #include "itkMacro.h"
 
 // Simplification of boost::common_type
-namespace itk
-{
+
 
 /// \cond HIDE_META_PROGRAMMING
-namespace mpl
+namespace itk::mpl
 {
 
 namespace Details
@@ -154,9 +153,8 @@ struct PromoteType
    */
   using Type = typename Details::SizeToType<sizeof Check(a + b, 0), TA, TB>::Type;
 };
-} // end namespace mpl
+} // namespace itk::mpl
 
 /// \endcond
-} // end namespace itk
 
 #endif // itkPromoteType_h

Modules/Core/Common/include/itkRandomVariateGeneratorBase.h

@@ -20,9 +20,7 @@
 
 #include "itkObject.h"
 
-namespace itk
-{
-namespace Statistics
+namespace itk::Statistics
 {
 /** \class RandomVariateGeneratorBase
  * \brief Defines common interfaces for random variate generators.
@@ -52,7 +50,6 @@ class ITKCommon_EXPORT RandomVariateGeneratorBase : public Object
 
 private:
 }; // end of class
-} // end of namespace Statistics
-} // end of namespace itk
+} // namespace itk::Statistics
 
 #endif

Modules/Core/Common/src/itkMath.cxx

@@ -17,9 +17,7 @@
  *=========================================================================*/
 #include "itkMath.h"
 
-namespace itk
-{
-namespace Math
+namespace itk::Math
 {
 
 namespace
@@ -115,5 +113,4 @@ GreatestPrimeFactor(unsigned long long n)
   return GreatestPrimeFactor<unsigned long long>(n);
 }
 
-} // end namespace Math
-} // end namespace itk
+} // namespace itk::Math

Modules/Core/Common/src/itkMersenneTwisterRandomVariateGenerator.cxx

@@ -21,9 +21,7 @@
 
 #include <atomic>
 
-namespace itk
-{
-namespace Statistics
+namespace itk::Statistics
 {
 namespace
 {
@@ -286,5 +284,4 @@ MersenneTwisterRandomVariateGenerator::PrintSelf(std::ostream & os, Indent inden
   os << indent << "Values left before next reload: " << m_Left << std::endl;
 }
 
-} // end namespace Statistics
-} // end namespace itk
+} // namespace itk::Statistics

Modules/Core/Common/src/itkRandomVariateGeneratorBase.cxx

@@ -17,11 +17,8 @@
  *=========================================================================*/
 #include "itkRandomVariateGeneratorBase.h"
 
-namespace itk
-{
-namespace Statistics
+namespace itk::Statistics
 {
 RandomVariateGeneratorBase::RandomVariateGeneratorBase() = default;
 RandomVariateGeneratorBase::~RandomVariateGeneratorBase() = default;
-} // end of namespace Statistics
-} // end of namespace itk
+} // namespace itk::Statistics