STYLE: Updated comments and variable in ImportImageContainer

Comments are variable name describe the behavior of the
ImportImageContainer better.
Closes InsightSoftwareConsortium#4359

Modules/Core/Common/include/itkImportImageContainer.h

@@ -118,12 +118,11 @@ class ITK_TEMPLATE_EXPORT ImportImageContainer : public Object
    * container. However, in this particular case, Reserve as a Resize
    * semantics that is kept for backward compatibility reasons.
    *
-   * If UseDefaultConstructor is true, then * the default constructor is used
-   * to initialize each element.  POD date types initialize to zero.
+   * If UseInitValue is true, then POD types will be zero-initialized.
    *
    * \sa SetImportPointer() */
   void
-  Reserve(ElementIdentifier size, const bool UseDefaultConstructor = false);
+  Reserve(ElementIdentifier size, const bool UseInitValue = false);
 
   /** Tell the container to try to minimize its memory usage for
    * storage of the current number of elements.  If new memory is
@@ -162,12 +161,11 @@ class ITK_TEMPLATE_EXPORT ImportImageContainer : public Object
   PrintSelf(std::ostream & os, Indent indent) const override;
 
   /**
-   * Allocates elements of the array.  If UseDefaultConstructor is true, then
-   * the default constructor is used to initialize each element.  POD date types
-   * initialize to zero.
+   * Allocates elements of the array.  If UseInitValue is true, then POD
+   * types will be zero-initialized.
    */
   virtual TElement *
-  AllocateElements(ElementIdentifier size, bool UseDefaultConstructor = false) const;
+  AllocateElements(ElementIdentifier size, bool UseInitValue = false) const;
 
   virtual void
   DeallocateManagedMemory();

Modules/Core/Common/include/itkImportImageContainer.hxx

@@ -44,7 +44,7 @@ ImportImageContainer<TElementIdentifier, TElement>::~ImportImageContainer()
  */
 template <typename TElementIdentifier, typename TElement>
 void
-ImportImageContainer<TElementIdentifier, TElement>::Reserve(ElementIdentifier size, const bool UseDefaultConstructor)
+ImportImageContainer<TElementIdentifier, TElement>::Reserve(ElementIdentifier size, const bool UseInitValue)
 {
   // Reserve has a Resize semantics. We keep it that way for
   // backwards compatibility .
@@ -53,7 +53,7 @@ ImportImageContainer<TElementIdentifier, TElement>::Reserve(ElementIdentifier si
   {
     if (size > m_Capacity)
     {
-      TElement * temp = this->AllocateElements(size, UseDefaultConstructor);
+      TElement * temp = this->AllocateElements(size, UseInitValue);
       // only copy the portion of the data used in the old buffer
       std::copy_n(m_ImportPointer, m_Size, temp);
 
@@ -73,7 +73,7 @@ ImportImageContainer<TElementIdentifier, TElement>::Reserve(ElementIdentifier si
   }
   else
   {
-    m_ImportPointer = this->AllocateElements(size, UseDefaultConstructor);
+    m_ImportPointer = this->AllocateElements(size, UseInitValue);
     m_Capacity = size;
     m_Size = size;
     m_ContainerManageMemory = true;
@@ -152,23 +152,19 @@ ImportImageContainer<TElementIdentifier, TElement>::SetImportPointer(TElement *
 
 template <typename TElementIdentifier, typename TElement>
 TElement *
-ImportImageContainer<TElementIdentifier, TElement>::AllocateElements(ElementIdentifier size,
-                                                                     bool              UseDefaultConstructor) const
+ImportImageContainer<TElementIdentifier, TElement>::AllocateElements(ElementIdentifier size, bool UseInitValue) const
 {
-  // Encapsulate all image memory allocation here to throw an
-  // exception when memory allocation fails even when the compiler
-  // does not do this by default.
   TElement * data;
 
   try
   {
-    if (UseDefaultConstructor)
+    if (UseInitValue)
     {
-      data = new TElement[size](); // POD types initialized to 0, others use default constructor.
+      data = new TElement[size]();
     }
     else
     {
-      data = new TElement[size]; // Faster but uninitialized
+      data = new TElement[size];
     }
   }
   catch (...)