Here are complete codes which can succeed to compile.
import strformat
import ../src/shene/mcall
# Constructor injection
type
Animal*[T] = object
sleepImpl: proc (a: T) {.nimcall, gcsafe.}
barkImpl: proc (a: T, b: int, c: int): string {.nimcall, gcsafe.}
danceImpl: proc (a: T, b: string): string {.nimcall, gcsafe.}
Phone*[T] = object
playImpl: proc (a: T) {.nimcall, gcsafe.}
Cat* = object
cid: int
Iphone* = object
pid: int
People*[T, U] = object
id: int
pet: must(Animal, T)
phone: must(Phone, U)
proc sleep*(a: Cat) =
discard
proc bark*(a: Cat, b: int, c: int): string =
result = fmt"{a.cid + b + c}"
proc dance*(a: Cat, b: string): string =
result = fmt"{b}"
proc play*(a: Phone) =
echo "Hello, the phone is playing the music."
proc play*(a: Iphone) =
echo "Hello, the iphone is playing the music."
proc initCat*(cid: int): must(Animal, Cat) =
result.cid = cid
result.sleepImpl = sleep
result.barkImpl = bark
result.danceImpl = dance
proc initPhone*(pid: int): must(Phone, Iphone) =
result.pid = pid
result.playImpl = play
proc initPeople*[T, U](pet: Must[Animal[T], T], phone: Must[Phone[U], U]):
People[T, U] =
result.id = 2333
result.pet = pet
result.phone = phone
proc prepare(p: People[Cat, Iphone]) =
doAssert p.pet.call(barkImpl, 13, 14) == "40"
p.pet.call(sleepImpl)
doAssert p.pet.call(danceImpl, "Hello") == "Hello"
doAssert p.pet.cid == 13
p.phone.call(playImpl)
doAssert p.phone.pid == 2333
let pet = initCat(13)
let phone = initPhone(2333)
let p = initPeople[Cat, Iphone](pet, phone)
prepare(p)
Run
