COMP: Fix TransformPhysicalPointToContinuousIndex nodiscard warnings

Did find code like this:

    ContinuousIndexType index;
    image->TransformPhysicalPointToContinuousIndex(point, index);

And replaced it by something like:

    const ContinuousIndexType index =
      image->template TransformPhysicalPointToContinuousIndex<ContinuousIndexValueType>(point);

When the `bool` return value is ignored, it is preferable to call the overload
that just returns the continuous index, preventing nodiscard compiler warnings.

These cases are found in Visual Studio, using the following regular expression:
`  [^ ]+->TransformPhysicalPointToContinuousIndex\(.*,`

Modules/Compatibility/Deprecated/include/itkVectorResampleImageFilter.hxx

@@ -114,7 +114,6 @@ VectorResampleImageFilter<TInputImage, TOutputImage, TInterpolatorPrecisionType>
   PointType inputPoint;  // Coordinates of current input pixel
 
   using ContinuousIndexType = ContinuousIndex<TInterpolatorPrecisionType, ImageDimension>;
-  ContinuousIndexType inputIndex;
 
   // Doc says this only works for VectorImage, but Image implementation says otherwise...
   const unsigned int numberOfComponents = this->GetInput()->GetNumberOfComponentsPerPixel();
@@ -131,7 +130,8 @@ VectorResampleImageFilter<TInputImage, TOutputImage, TInterpolatorPrecisionType>
 
     // Compute corresponding input pixel position
     inputPoint = m_Transform->TransformPoint(outputPoint);
-    inputPtr->TransformPhysicalPointToContinuousIndex(inputPoint, inputIndex);
+    const ContinuousIndexType inputIndex =
+      inputPtr->template TransformPhysicalPointToContinuousIndex<TInterpolatorPrecisionType>(inputPoint);
 
     // Evaluate input at right position and copy to the output
     if (m_Interpolator->IsInsideBuffer(inputIndex))

Modules/Core/ImageFunction/include/itkBSplineInterpolateImageFunction.h

@@ -180,9 +180,9 @@ class ITK_TEMPLATE_EXPORT BSplineInterpolateImageFunction : public InterpolateIm
   CovariantVectorType
   EvaluateDerivative(const PointType & point) const
   {
-    ContinuousIndexType index;
+    const ContinuousIndexType index =
+      this->GetInputImage()->template TransformPhysicalPointToContinuousIndex<TCoordRep>(point);
 
-    this->GetInputImage()->TransformPhysicalPointToContinuousIndex(point, index);
     // No thread info passed in, so call method that doesn't need thread ID.
     return (this->EvaluateDerivativeAtContinuousIndex(index));
   }
@@ -222,9 +222,8 @@ class ITK_TEMPLATE_EXPORT BSplineInterpolateImageFunction : public InterpolateIm
   void
   EvaluateValueAndDerivative(const PointType & point, OutputType & value, CovariantVectorType & deriv) const
   {
-    ContinuousIndexType index;
-
-    this->GetInputImage()->TransformPhysicalPointToContinuousIndex(point, index);
+    const ContinuousIndexType index =
+      this->GetInputImage()->template TransformPhysicalPointToContinuousIndex<TCoordRep>(point);
 
     // No thread info passed in, so call method that doesn't need thread ID.
     this->EvaluateValueAndDerivativeAtContinuousIndex(index, value, deriv);

Modules/Core/ImageFunction/include/itkImageFunction.h

@@ -191,7 +191,7 @@ class ITK_TEMPLATE_EXPORT ImageFunction : public FunctionBase<Point<TCoordRep, T
   void
   ConvertPointToContinuousIndex(const PointType & point, ContinuousIndexType & cindex) const
   {
-    m_Image->TransformPhysicalPointToContinuousIndex(point, cindex);
+    cindex = m_Image->template TransformPhysicalPointToContinuousIndex<TCoordRep>(point);
   }
 
   /** Convert continuous index to nearest index. */

Modules/Nonunit/Review/test/itkDiscreteGaussianDerivativeImageFunctionTest.cxx

@@ -138,9 +138,7 @@ itkDiscreteGaussianDerivativeImageFunctionTestND(int argc, char * argv[])
   out.GoToBegin();
 
   using PointType = typename GaussianDerivativeImageFunctionType::PointType;
-  PointType point;
-  using ContinuousIndexType = typename GaussianDerivativeImageFunctionType::ContinuousIndexType;
-  ContinuousIndexType cindex;
+  PointType           point;
   const unsigned long nop = inputImage->GetRequestedRegion().GetNumberOfPixels();
   unsigned long       pixelNumber = 0;
   while (!it.IsAtEnd())
@@ -157,8 +155,12 @@ itkDiscreteGaussianDerivativeImageFunctionTestND(int argc, char * argv[])
     }
     else
     {
+      using ContinuousIndexType = typename GaussianDerivativeImageFunctionType::ContinuousIndexType;
+      using ContinuousIndexValueType = typename ContinuousIndexType::ValueType;
+
       inputImage->TransformIndexToPhysicalPoint(it.GetIndex(), point);
-      inputImage->TransformPhysicalPointToContinuousIndex(point, cindex);
+      const ContinuousIndexType cindex =
+        inputImage->template TransformPhysicalPointToContinuousIndex<ContinuousIndexValueType>(point);
       out.Set(function->EvaluateAtContinuousIndex(cindex));
     }
     ++it;

Modules/Nonunit/Review/test/itkDiscreteGradientMagnitudeGaussianImageFunctionTest.cxx

@@ -139,9 +139,7 @@ itkDiscreteGradientMagnitudeGaussianImageFunctionTestND(int argc, char * argv[])
   out.GoToBegin();
 
   using PointType = typename DiscreteGradientMagnitudeGaussianFunctionType::PointType;
-  PointType point;
-  using ContinuousIndexType = typename DiscreteGradientMagnitudeGaussianFunctionType::ContinuousIndexType;
-  ContinuousIndexType cindex;
+  PointType           point;
   const unsigned long nop = inputImage->GetRequestedRegion().GetNumberOfPixels();
   unsigned long       pixelNumber = 0;
   while (!it.IsAtEnd())
@@ -158,8 +156,12 @@ itkDiscreteGradientMagnitudeGaussianImageFunctionTestND(int argc, char * argv[])
     }
     else
     {
+      using ContinuousIndexType = typename DiscreteGradientMagnitudeGaussianFunctionType::ContinuousIndexType;
+      using ContinuousValueIndexType = typename ContinuousIndexType::ContinuousIndexType;
+
       inputImage->TransformIndexToPhysicalPoint(it.GetIndex(), point);
-      inputImage->TransformPhysicalPointToContinuousIndex(point, cindex);
+      const ContinuousIndexType cindex =
+        inputImage->TransformPhysicalPointToContinuousIndex<ContinuousValueIndexType>(point);
       out.Set(function->EvaluateAtContinuousIndex(cindex));
     }
     ++it;

Modules/Nonunit/Review/test/itkDiscreteHessianGaussianImageFunctionTest.cxx

@@ -132,9 +132,7 @@ itkDiscreteHessianGaussianImageFunctionTestND(int argc, char * argv[])
   IteratorType outIter(output, output->GetRequestedRegion());
 
   using PointType = typename HessianGaussianImageFunctionType::PointType;
-  PointType point;
-  using ContinuousIndexType = typename HessianGaussianImageFunctionType::ContinuousIndexType;
-  ContinuousIndexType cindex;
+  PointType           point;
   const unsigned long nop = reader->GetOutput()->GetRequestedRegion().GetNumberOfPixels();
   unsigned long       pixelNumber = 0;
   while (!it.IsAtEnd())
@@ -150,8 +148,12 @@ itkDiscreteHessianGaussianImageFunctionTestND(int argc, char * argv[])
     }
     else
     {
+      using ContinuousIndexType = typename HessianGaussianImageFunctionType::ContinuousIndexType;
+      using ContinuousIndexValueType = typename ContinuousIndexType::ValueType;
+
       reader->GetOutput()->TransformIndexToPhysicalPoint(it.GetIndex(), point);
-      reader->GetOutput()->TransformPhysicalPointToContinuousIndex(point, cindex);
+      const ContinuousIndexType cindex =
+        reader->GetOutput()->TransformPhysicalPointToContinuousIndex<ContinuousIndexValueType>(point);
       hessian = function->EvaluateAtContinuousIndex(cindex);
     }