This code basically does what I may want
type
O[X] = object
i: int
x: X
proc d[X](o: O[X]) =
when type(o.x) is bool: echo "yes" else: echo "no"
var h1: O[bool]
var h2: O[int8]
d(h1)
d(h2)
yes
no
But of course it is strange to use an arbitrary data type field just to get a
compile time decision.
The reason why I may want that is, that I have generic data types, which for
special use cases allow optimizations. But I do not want to code all procs
working on these data types twice, and I can not use "when (defined)" because
decision is for individual instances. Indeed it is for a Robin-Hood Hash Table,
where for some cases optimizations are possible. But the optimization is not
really based on the key data type, but more on the used equality test, so
something like "when type(key) is string" is not the best solution. Well, maybe
I will find a solution in the manual...
[EDIT]
Well, I could delete this posting:
>From manual: "The is operator checks for type equivalence at compile time." So
>it is exactly what I need. I was confused, thought it is a runtime check.
