Weak Purity Blog Post

[ag0aep6g via Digitalmars-d-announce]

On 28.03.2016 03:44, sarn wrote:
> https://theartofmachinery.com/2016/03/28/dirtying_pure_functions_can_be_useful.html

 From there:

> Well, you can get the usual (“strong”) purity guarantee just by making all pointer or reference type arguments const.

Indirections in the return type also play into this. David Nadlinger 
explains this in his article on the matter:

http://klickverbot.at/blog/2012/05/purity-in-d/#indirections-in-the-return-type