[vtkusers] Cast doubt on method vtkFloatArray::GetTuple

[Renato N. Elias]

Just a minor doubt (or curiosity):

Since vtkFloatArray is a float type, why (or how) does the GetTuple 
method return a double?

I'm using a vtkFloatArray to point to the output of a normals generation 
filter. In this case, I had to performe a "SafeDownCast" from the output 
of the normals filter to the vtkFloatArray. After that, when I was 
getting the tuples from vtkFloatArray I noticed that the method returns 
a double (again). Well, although not being a C++ programmer, it seemed a 
bit weird. Is it safe (or even common in C++)?

Thanks for any clarification

Renato.