From 824b041b212d977da83187e4a06c8037789ba48a Mon Sep 17 00:00:00 2001
From: Niels Dekker <N.Dekker@lumc.nl>
Date: Thu, 21 Sep 2023 14:12:22 +0200
Subject: [PATCH] STYLE: Default constructors VectorContainer, Iterator,
 ConstIterator

Defaulted the default-constructors of `VectorContainer`,
`VectorContainer::Iterator`, and `VectorContainer::ConstIterator`. Added
in-class default member initializers to their member variables.

Added `[[maybe_unused]]` attributes to itkVectorContainerTest, to avoid Clang
warnings ("unused variable 'p_null' [-Wunused-variable]") which would otherwise
appear when defaulting those default-constructors.
---
 .../Core/Common/include/itkVectorContainer.h  | 21 +++++++------------
 .../Common/test/itkVectorContainerTest.cxx    | 16 +++++++-------
 2 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/Modules/Core/Common/include/itkVectorContainer.h b/Modules/Core/Common/include/itkVectorContainer.h
index fa35193be77..315d2578efa 100644
--- a/Modules/Core/Common/include/itkVectorContainer.h
+++ b/Modules/Core/Common/include/itkVectorContainer.h
@@ -71,10 +71,7 @@ class ITK_TEMPLATE_EXPORT VectorContainer
   /** Provide pass-through constructors corresponding to all the STL
    * vector constructors.  These are for internal use only since this is also
    * an Object which must be constructed through the "New()" routine. */
-  VectorContainer()
-    : Object()
-    , VectorType()
-  {}
+  VectorContainer() = default;
   VectorContainer(size_type n)
     : Object()
     , VectorType(n)
@@ -185,9 +182,7 @@ class ITK_TEMPLATE_EXPORT VectorContainer
     using pointer = typename VectorIterator::pointer;
     using reference = typename VectorIterator::reference;
 
-    Iterator()
-      : m_Pos(0)
-    {}
+    Iterator() = default;
     Iterator(size_type d, const VectorIterator & i)
       : m_Pos(d)
       , m_Iter(i)
@@ -292,8 +287,8 @@ class ITK_TEMPLATE_EXPORT VectorContainer
     }
 
   private:
-    size_type      m_Pos;
-    VectorIterator m_Iter;
+    size_type      m_Pos{};
+    VectorIterator m_Iter{};
     friend class ConstIterator;
   };
 
@@ -311,9 +306,7 @@ class ITK_TEMPLATE_EXPORT VectorContainer
     using pointer = typename VectorConstIterator::pointer;
     using reference = typename VectorConstIterator::reference;
 
-    ConstIterator()
-      : m_Pos(0)
-    {}
+    ConstIterator() = default;
     ConstIterator(size_type d, const VectorConstIterator & i)
       : m_Pos(d)
       , m_Iter(i)
@@ -428,8 +421,8 @@ class ITK_TEMPLATE_EXPORT VectorContainer
     }
 
   private:
-    size_type           m_Pos;
-    VectorConstIterator m_Iter;
+    size_type           m_Pos{};
+    VectorConstIterator m_Iter{};
     friend class Iterator;
   };
 
diff --git a/Modules/Core/Common/test/itkVectorContainerTest.cxx b/Modules/Core/Common/test/itkVectorContainerTest.cxx
index 1b4e80fd758..5e24832a46c 100644
--- a/Modules/Core/Common/test/itkVectorContainerTest.cxx
+++ b/Modules/Core/Common/test/itkVectorContainerTest.cxx
@@ -33,10 +33,10 @@ itkVectorContainerTest(int, char *[])
 
   // Iterator
   {
-    ContainerType::Iterator p_null;
-    ContainerType::Iterator p = container->Begin();
-    ContainerType::Iterator p_copy(p);
-    ContainerType::Iterator p_assign = p;
+    [[maybe_unused]] ContainerType::Iterator p_null;
+    ContainerType::Iterator                  p = container->Begin();
+    ContainerType::Iterator                  p_copy(p);
+    ContainerType::Iterator                  p_assign = p;
 
     while (p != container->End())
     {
@@ -51,10 +51,10 @@ itkVectorContainerTest(int, char *[])
 
   // ConstIterator
   {
-    ContainerType::ConstIterator p_null;
-    ContainerType::ConstIterator p = container->Begin();
-    ContainerType::ConstIterator p_copy(p);
-    ContainerType::ConstIterator p_assign = p;
+    [[maybe_unused]] ContainerType::ConstIterator p_null;
+    ContainerType::ConstIterator                  p = container->Begin();
+    ContainerType::ConstIterator                  p_copy(p);
+    ContainerType::ConstIterator                  p_assign = p;
 
     while (p != container->End())
     {