Should Atoms.get_chemical_indices() return pointer?

[samwaseda]

I find the following lines a bit counterintuitive.

>>> structure = pr.create.structure.bulk('Al', cubic=True)
>>> structure[0] = 'Fe'
>>> indices = structure.get_chemical_indices()
>>> print(indices)
>>> structure[:] = 'Al'
>>> print(indices)
[1 0 0 0]
[0 0 0 0]

I would rather expect that Atoms.get_chemical_indices() returns a copy of the indices and not the pointer, also because changing indices has (for some reason) no effect on the atom species. But before I start changing this I just wanted to make sure that this is not the desired behaviour. @sudarsan-surendralal @pmrv @jan-janssen

[sudarsan-surendralal]

I agree, this should not return a pointer. Go ahead with the changes!

[liamhuber]

Also agreed. It's sometimes nice to have a pointer, but I would say structure.indices -> pointer; while structure.get_chemical_indices() -> new array as you suggest here.