Weak Purity Blog Post

[sarn via Digitalmars-d-announce]

D's implementation of functional purity supports "weak" purity - 
functions that can mutate arguments but are otherwise 
traditionally pure.

I wrote a post about some of the practical benefits of this kind 
of purity:

https://theartofmachinery.com/2016/03/28/dirtying_pure_functions_can_be_useful.html