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This module provides basic primitives for creating parallel programs. A Task should be only owned by a single Thread, it cannot be shared by threads.

Example: cmd: --gc:orc

import std/tasks
block:
  var num = 0
  proc hello(a: int) = inc num, a

  let b = toTask hello(13)
  b.invoke()
  assert num == 13
  # A task can be invoked multiple times
  b.invoke()
  assert num == 26

block:
  type
    Runnable = ref object
      data: int

  var data: int
  proc hello(a: Runnable) {.nimcall.} =
    a.data += 2
    data = a.data


  when false:
    # the parameters of call must be isolated.
    let x = Runnable(data: 12)
    let b = toTask hello(x) # error ----> expression cannot be isolated: x
    b.invoke()

  let b = toTask(hello(Runnable(data: 12)))
  b.invoke()
  assert data == 14
  b.invoke()
  assert data == 16