Wondering if we really need a `declare` syntax; can't type conversions be used
for this?
Instead of:
declare seq[T] is Container[T]
we'd have:
proc seqIsAContainer[T](s: seq[T]): Container[T] =
Container[T](s)
([http://nim-lang.org/docs/manual.html#statements-and-expressions-type-conversions](http://forum.nim-lang.org///nim-lang.org/docs/manual.html#statements-and-expressions-type-conversions))
I guess what I'm saying is perhaps `declare` is just a `template` (aka syntax
sugar) along the lines of:
template declare(t1: typed, t2: typed) =
when not (t1 is t2):
{.error: $t1 % " does not match " % $t2 .}
proc declare(tt: t1): t2 =
t2(tt)
Just an idea.
