Emit a #warning when a host fallback path is encountered

[GoogleCodeExporter]

We currently silently dispatch host fallback paths for a subset of 
device_vector functionality.  These can easily cause bottlenecks.  We should 
notify the user when this happens with an optional warning.

Original issue reported on code.google.com by jaredhoberock on 17 May 2010 at 9:45

[GoogleCodeExporter]

I don't know of a way to do this -- there is no static_warn analogous to 
static_assert.  Using #warning would emit a warning simply by #including this 
header, whether or not the fallback code path was actually instantiated.

Original comment by jaredhoberock on 6 Aug 2010 at 11:54

• Changed state: WontFix

[GoogleCodeExporter]

implementing the enhancement in issue #56 would mitigate this problem to a 
large degree

Original comment by wnbell on 7 Aug 2010 at 12:06