On Thursday, 20 February 2014 at 00:36:38 UTC, anonymous wrote:
On Wednesday, 19 February 2014 at 22:46:45 UTC, Chris Williams
wrote:
When the template writes out the definition of the function,
if the parameters can be interpreted during compile-time, then
the foreach ( O(n) ) will be run by the compiler to detect the
correct parameter and the function will be written out as just
as a return statement in the body, without the loop. So during
runtime, the function would have an O(1) runtime.
That's an optimization the compiler may do, but it's not
guaranteed. And `among` is not special in this regard.
I think "expected to do" is probably the better phrasing at the
moment. Traits/annotations would be largely unusable unless
foreach was able to behave as a static construct. And since there
is no way for one to declare "static foreach", the only way
foreach can be used for running over traits, is for the compiler
to detect constant values in the parameters to the statement.
