diff --git a/Modules/IGT/Algorithms/mitkNavigationDataDelayFilter.cpp b/Modules/IGT/Algorithms/mitkNavigationDataDelayFilter.cpp
index 3d866f3d1c..817f02b29d 100644
--- a/Modules/IGT/Algorithms/mitkNavigationDataDelayFilter.cpp
+++ b/Modules/IGT/Algorithms/mitkNavigationDataDelayFilter.cpp
@@ -1,79 +1,79 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "mitkNavigationDataDelayFilter.h"
 
 mitk::NavigationDataDelayFilter::NavigationDataDelayFilter(unsigned int delay) : m_Delay(delay)
 {
   m_Tolerance = 0;
 }
 mitk::NavigationDataDelayFilter::~NavigationDataDelayFilter()
 {
 }
 
 void mitk::NavigationDataDelayFilter::GenerateData()
 {
   // Check if number of outputs has changed since the previous call. If yes, reset buffer.
   // This actually compares the number of Navigation Datas in each step and compares it to the current number of inputs.
   // If these values differ, the number of inputrs have changed.
-  if ( (m_Buffer.size() > 0) &&  (this->GetNumberOfInputs() != m_Buffer.front().second.size()) )
-    std::swap(m_Buffer, decltype(m_Buffer)()); // Clear queue with copy-and-swap idiom
+  if ((!m_Buffer.empty()) && (this->GetNumberOfInputs() != m_Buffer.front().second.size()))
+    m_Buffer.swap(decltype(m_Buffer)()); // Clear queue with copy-and-swap idiom
 
   // Put current navigationdatas from input into buffer
   itk::TimeStamp now;
   now.Modified();
 
   std::vector<mitk::NavigationData::Pointer> ndList;
   for (unsigned int i = 0; i < this->GetNumberOfInputs() ; ++i)
   {
     mitk::NavigationData::Pointer nd = mitk::NavigationData::New();
     nd->Graft(this->GetInput(i));
     ndList.push_back(nd);
   }
 
   m_Buffer.push( std::make_pair(now.GetMTime(), ndList) );
 
   // Find most recent member from buffer that is old enough to output, considering the Delay
   // remove all sets that are too old already in the process
   BufferType current;
   bool foundCurrent = false;
 
   while ( (m_Buffer.size() > 0) && (m_Buffer.front().first + m_Delay <= now.GetMTime() + m_Tolerance ) )
   {
     foundCurrent = true;
     current = m_Buffer.front();
     m_Buffer.pop();
   }
 
   // update outputs with tracking data from previous step, or none if empty
   if ( !foundCurrent) return;
 
   for (unsigned int i = 0; i < this->GetNumberOfOutputs() ; ++i)
   {
     mitk::NavigationData* output = this->GetOutput(i);
     assert(output);
     const mitk::NavigationData* input = current.second[i];
     assert(input);
 
     if (input->IsDataValid() == false)
     {
       output->SetDataValid(false);
       continue;
     }
     output->Graft(input); // First, copy all information from input to output
     output->SetDataValid(true); // operation was successful, therefore data of output is valid.
   }
 }
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