Thanks... that was very helpful.
I played around with the following playground. I think I understand it. Now to
integrate into production code.
proc createUncheckedArray(n: int): ptr UncheckedArray[int] =
cast[ptr UncheckedArray[int]](cast[pointer](alloc(n * sizeof(int))))
# Syntactic sugar
template withLength(elements: untyped, length: int): untyped =
toOpenArray(elements, 0, length - 1)
when isMainModule:
import algorithm
# Simple assertion check
template shouldBe[T](elements: untyped, answer: openArray[T]): untyped =
assert (elements.withLength length) == answer
proc init_0_to_n(elements: var openArray[int]) =
for i in 0 .. elements.high:
elements[i] = i + 1
proc double(elements: var openArray[int]) =
for i in 0 .. elements.high:
elements[i] *= 2
const length = 4
var elements = createUncheckedArray length
# Populate the UncheckedArray
init_0_to_n(elements.withLength length)
elements.shouldBe [1, 2, 3, 4]
double elements.withLength length
elements.shouldBe [2, 4, 6, 8]
# Descending sort
(elements.withLength length).sort do (a, b: int) -> int: b.cmp a
elements.shouldBe [8, 6, 4, 2]
dealloc elements
Run
