Slides from my ACCU Silicon Valley talk

[Jonathan M Davis]

On Monday 13 December 2010 04:05:33 bearophile wrote:
> Jonathan M Davis:
> > I don't see what that poster thought would be gained by enforcing that,
> 
> If you read that part in the Reddit thread you see that the gain is in a
> (supposed) higher understandability of the code that uses the operators.
> 
> > but it's _really_ easy to have useful and legitimate overloaded operators
> > which can't be pure.
> 
> Do you have examples?

At the momement, pretty much none of the operator overloads in std.datetime are 
pure, and while some of them _may_ be able to become pure with the pure nothrow 
bug fixed, I don't think that they'll all be able to. All it takes is _one_ 
function in the whole call chain which can't be pure, and then _none_ of them 
can pure. It's _really_ easy to make purity not possible. Things will improve as 
more of Phobos becomes pure, but forcing stuff to be pure is generally a _bad_ 
idea.

- Jonathan M Davis