Value ranges for slices, and more enum preconditions

[bearophile via Digitalmars-d]

After thinking a bit more about this topic I have opened an ER, 
because I think this could statically catch some slice-related 
bugs and allow some safe implicit casts:

https://issues.dlang.org/show_bug.cgi?id=13228

Just a curiosity of mine: Do you remember who originally proposed 
to add the value range analysis to D (and the link to the 
posts/discussion)?

Bye,
bearophile