STYLE: Use std::next in LabelMap::GetNthLabelObject

Somewhat simplified their implementations.
InsightSoftwareConsortium · Jan 18, 2024 · f844df9 · f844df9
1 parent 1deea1e
commit f844df9
Showing 1 changed file with 8 additions and 22 deletions.
diff --git a/Modules/Filtering/LabelMap/include/itkLabelMap.hxx b/Modules/Filtering/LabelMap/include/itkLabelMap.hxx
@@ -183,39 +183,25 @@ template <typename TLabelObject>
 auto
 LabelMap<TLabelObject>::GetNthLabelObject(const LabelMap::SizeValueType & pos) -> LabelObjectType *
 {
-  SizeValueType i = 0;
-
-  for (auto it = m_LabelObjectContainer.begin(); it != m_LabelObjectContainer.end(); ++it)
+  if (const auto numberOfLabelObjects = m_LabelObjectContainer.size(); numberOfLabelObjects <= pos)
   {
-    if (i == pos)
-    {
-      return it->second;
-    }
-    ++i;
+    itkExceptionMacro("Can't access label object at position " << pos << ". The label map has only "
+                                                               << numberOfLabelObjects << " label objects registered.");
   }
-  itkExceptionMacro("Can't access to label object at position " << pos << ". The label map has only "
-                                                                << this->GetNumberOfLabelObjects()
-                                                                << " label objects registered.");
+  return std::next(m_LabelObjectContainer.cbegin(), pos)->second;
 }
 
 
 template <typename TLabelObject>
 auto
 LabelMap<TLabelObject>::GetNthLabelObject(const LabelMap::SizeValueType & pos) const -> const LabelObjectType *
 {
-  SizeValueType i = 0;
-
-  for (LabelObjectContainerConstIterator it = m_LabelObjectContainer.begin(); it != m_LabelObjectContainer.end(); ++it)
+  if (const auto numberOfLabelObjects = m_LabelObjectContainer.size(); numberOfLabelObjects <= pos)
   {
-    if (i == pos)
-    {
-      return it->second;
-    }
-    ++i;
+    itkExceptionMacro("Can't access label object at position " << pos << ". The label map has only "
+                                                               << numberOfLabelObjects << " label objects registered.");
   }
-  itkExceptionMacro("Can't access to label object at position " << pos << ". The label map has only "
-                                                                << this->GetNumberOfLabelObjects()
-                                                                << " label objects registered.");
+  return std::next(m_LabelObjectContainer.cbegin(), pos)->second;
 }