I wouldn't recommend using converter as it makes your code less readable and
can often create ambiguity when compiling, especially for something as trivial
as an assignment.
You could rewrite your code as this :
type SEQ*[T] = object
data*: seq[T]
proc asSEQ*[T](x: seq[T]) : SEQ[T] =
result.data = x
proc initSEQ*[T](n: int): SEQ[T] =
SEQ[T](data: newSeq[T](n))
# [] operator
proc `[]`*[T](self: SEQ[T], i: int): T =
self.data[i]
proc `[]=`*[T](self: var SEQ[T], i: int, val: T) =
var d = self.data
d[i] = val
# No need to return a if passed as a var parameters
proc f*[T](a: var SEQ[T]) =
a[0] = 1
when isMainModule:
var a: SEQ[int] = @[1, 2, 3].asSEQ # I want to define this way by
converter
f(a)
echo a[0]
Run
