ENH: Make Vector construction from scalar value explicit

This prevents unintentional conversion of a scalar value into a Vector
filled with that value.

For example, when assigning the result of a Vector dot product back to
another Vector without an explicit usage of the Vector constructor,
a compilation error will now be raised.

Thanks to Wang Chengjia and Tim Allman for reporting this issue.

COMP: Keep deprecated version around unless ITK_FUTURE_LEGACY_REMOVE

Use of ::Zero is deprecated since commit 3f712cd.

Change-Id: Ie64b73af31390f9b6bc34912cf62be627fb815a0

Modules/Core/Common/include/itkVector.h

@@ -110,8 +110,17 @@ class Vector:public FixedArray< T, NVectorDimension >
   /** Default constructor and copy constructors. */
   Vector():BaseArray() {}
 
-  /** Constructor to initialize entire vector to one value. */
+#if !defined( ITK_LEGACY_FUTURE_REMOVE )
+  /** Constructor to initialize entire vector to one value.
+   * \warning Not intended to convert a scalar value into
+   * a Vector filled with that value.
+   * \deprecated */
   Vector(const ValueType & r);
+#else
+  /** Constructor to initialize entire vector to one value,
+   * if explicitly invoked. */
+  explicit Vector(const ValueType & r);
+#endif
 
   /** Pass-through constructor for the Array base class. */
   template< typename TVectorValueType >

Modules/Core/QuadEdgeMesh/include/itkQuadEdgeMeshToQuadEdgeMeshFilter.h

@@ -165,8 +165,9 @@ void CopyMeshToMeshCellData(const TInputMesh *in, TOutputMesh *out)
   InputCellDataContainerConstIterator inIt = inputCellData->Begin();
   while ( inIt != inputCellData->End() )
     {
-    outputCellData->SetElement( inIt.Index(), inIt.Value() );
-    inIt++;
+    typename OutputCellDataContainer::Element point(inIt.Value());
+    outputCellData->SetElement( inIt.Index(), point );
+    ++inIt;
     }
 
   out->SetCellData(outputCellData);
@@ -196,7 +197,8 @@ void CopyMeshToMeshPointData(const TInputMesh *in, TOutputMesh *out)
   InputPointDataContainerConstIterator inIt = inputPointData->Begin();
   while ( inIt != inputPointData->End() )
     {
-    outputPointData->SetElement( inIt.Index(), inIt.Value() );
+    typename OutputPointDataContainer::Element point( inIt.Value() );
+    outputPointData->SetElement( inIt.Index(), point );
     inIt++;
     }
 

Modules/Core/SpatialObjects/include/itkTubeSpatialObject.hxx

@@ -152,7 +152,7 @@ TubeSpatialObject< TDimension, TTubePointType >
       {
       // First we compute the bounding box in the index space
       typename BoundingBoxType::Pointer bb = BoundingBoxType::New();
-      VectorType rad = ( *it ).GetRadius();
+      VectorType rad(( *it ).GetRadius());
       PointType ptMin = ( *it ).GetPosition() - rad;
       PointType ptMax = ( *it ).GetPosition() + rad;
       bb->SetMinimum(ptMin);
@@ -166,7 +166,7 @@ TubeSpatialObject< TDimension, TTubePointType >
       it++;
       while ( it != end )
         {
-        rad = ( *it ).GetRadius();
+        rad = VectorType(( *it ).GetRadius());
         ptMin = ( *it ).GetPosition() - rad;
         ptMax = ( *it ).GetPosition() + rad;
         bb->ConsiderPoint(ptMin);

Modules/Core/SpatialObjects/test/itkSpatialObjectToImageStatisticsCalculatorTest.cxx

@@ -68,7 +68,7 @@ int itkSpatialObjectToImageStatisticsCalculatorTest(int, char * [] )
   std::cout << "Sample mean = " << calculator->GetMean() << std::endl;
   std::cout << "Sample covariance = " << calculator->GetCovarianceMatrix();
 
-  if(calculator->GetMean() != 255
+  if(calculator->GetMean() != CalculatorType::VectorType(255)
     || calculator->GetCovarianceMatrix()[0][0] != 0
     )
     {

Modules/Filtering/ImageGrid/include/itkBSplineScatteredDataPointSetToImageFilter.hxx

@@ -473,7 +473,7 @@ BSplineScatteredDataPointSetToImageFilter<TInputPointSet, TOutputImage>
       this->m_DeltaLatticePerThread[n] = PointDataImageType::New();
       this->m_DeltaLatticePerThread[n]->SetRegions( size );
       this->m_DeltaLatticePerThread[n]->Allocate();
-      this->m_DeltaLatticePerThread[n]->FillBuffer( 0.0 );
+      this->m_DeltaLatticePerThread[n]->FillBuffer( NumericTraits<PointDataType>::Zero );
       }
     }
 }
@@ -852,7 +852,7 @@ BSplineScatteredDataPointSetToImageFilter<TInputPointSet, TOutputImage>
     this->m_PhiLattice = PointDataImageType::New();
     this->m_PhiLattice->SetRegions( size );
     this->m_PhiLattice->Allocate();
-    this->m_PhiLattice->FillBuffer( 0.0 );
+    this->m_PhiLattice->FillBuffer( NumericTraits<PointDataType>::Zero );
 
     ImageRegionIterator<PointDataImageType> ItP(
       this->m_PhiLattice, this->m_PhiLattice->GetLargestPossibleRegion() );

Modules/Filtering/ImageGrid/test/itkBSplineControlPointImageFunctionTest.cxx

@@ -46,7 +46,7 @@ int itkBSplineControlPointImageFunctionTest( int, char * [] )
   phiLattice->SetSpacing( spacing );
   phiLattice->SetRegions( size );
   phiLattice->Allocate();
-  phiLattice->FillBuffer( 0.0 );
+  phiLattice->FillBuffer( VectorType(0.0) );
 
   // To create the specified function, the first and last control points have
   // a value of 1.0;

Modules/Filtering/ImageGrid/test/itkWarpVectorImageFilterTest.cxx

@@ -131,7 +131,7 @@ int itkWarpVectorImageFilterTest(int, char* [] )
 
   for( Iterator inIter( input, region ); !inIter.IsAtEnd(); ++inIter )
     {
-    inIter.Set( pattern.Evaluate( inIter.GetIndex(), size, size, padValue ) );
+    inIter.Set( PixelType(pattern.Evaluate( inIter.GetIndex(), size, size, padValue )) );
     }
 
   //=============================================================
@@ -175,7 +175,7 @@ int itkWarpVectorImageFilterTest(int, char* [] )
 
   warper->SetInput( input );
   warper->SetDisplacementField( field );
-  warper->SetEdgePaddingValue( padValue );
+  warper->SetEdgePaddingValue( PixelType(padValue) );
 
   ShowProgressObject progressWatch(warper);
   itk::SimpleMemberCommand<ShowProgressObject>::Pointer command;
@@ -266,7 +266,7 @@ int itkWarpVectorImageFilterTest(int, char* [] )
     if( validRegion.IsInside( index ) )
       {
 
-    PixelType trueValue = pattern.Evaluate( outIter.GetIndex(), validSize, clampSize, padValue );
+      PixelType trueValue(pattern.Evaluate( outIter.GetIndex(), validSize, clampSize, padValue));
       for( unsigned int k=0; k<ImageDimension; k++ )
         {
         if( vnl_math_abs( trueValue[k] - value[k] ) > 1e-4 )
@@ -282,7 +282,7 @@ int itkWarpVectorImageFilterTest(int, char* [] )
     else
       {
 
-      if( value != padValue )
+      if( value != PixelType(padValue) )
         {
         testPassed = false;
         std::cout << "Error at Index: " << index << " ";

Modules/Numerics/Optimizersv4/include/itkWindowConvergenceMonitoringFunction.hxx

@@ -104,7 +104,7 @@ WindowConvergenceMonitoringFunction<TScalar>
     windowPoint[0] = static_cast<typename ProfilePointType::CoordRepType>( n );
 
     energyProfileWindow->SetPoint( n, windowPoint );
-    energyProfileWindow->SetPointData( n, this->m_EnergyValues[n] / this->m_TotalEnergy );
+    energyProfileWindow->SetPointData( n, ProfilePointDataType(this->m_EnergyValues[n] / this->m_TotalEnergy) );
     }
 
   bspliner->SetInput( energyProfileWindow );

Modules/Registration/FEM/test/itkFEMFiniteDifferenceFunctionLoadTest.cxx

@@ -235,7 +235,7 @@ int RunTest(testImageType* fixed, testImageType* moving, FieldType* initField,
   // Test ApplyLoad() function
   FieldType::PixelType pixelVal;
   for (unsigned int d = 0; d < ImageDimension; d++)
-    pixelVal = 0.0;
+    pixelVal = FieldType::PixelType( 0.0 );
   outField->FillBuffer(pixelVal);
   const FieldType::RegionType& region = outField->GetLargestPossibleRegion();