On Wednesday, 16 March 2016 at 11:18:36 UTC, Johan Engelen wrote:
Hi all,
I've found discussions, but not an actual "recommended"
solution for the problem of "statement is not reachable"
warnings in templates with early returns...
"statement is not reachable" is fundamentally broken in D for
generic code:
https://issues.dlang.org/show_bug.cgi?id=14835
It's mostly not too big of a deal right now, only because the D
front end's value range propagation capabilities are very weak.
Lionello Lunesu made a pull request a while back that majorly
improves VRP in D as a part of his efforts to fix DMD issue 259.
I decided to port it to DDMD a few months ago, and in the process
discovered that with decent VRP, issue 14835 becomes 10-100x
worse.
There was a forum discussion a while back as to what should be
done about this, but unfortunately the conclusion was that it
probably cannot really be fixed with any reasonable effort:
http://forum.dlang.org/thread/bnzfuekewfguvnwdz...@forum.dlang.org
As far as I can tell, the only reasonable way forward is to
simply remove the warning entirely (or ban meaningful upgrades to
VRP).
