How to get array from ITK image without using loop?

Maybe have a function return a pointer or copy memory to a given pointer.

SimpleITK::Image has a lot of methods that return the pointer as you need:

https://simpleitk.org/doxygen/latest/html/classitk_1_1simple_1_1Image.html

you might want: SimpleITK::Image::GetBufferAsVoid()

or other ones ...