Typeinfo Mk 2

import typeinfo

type
  Parent = object of RootObj
    x: int
  Child = object of Parent
    y: string

type CustomAny* = object
    value: pointer
    rawType: pointer

proc customToAny*[T](x: var T): CustomAny {.inline.} =
  result = cast[CustomAny](toAny(x))

proc compareRuntimeTypes[A, B](a: var A, b: var B): bool =
  result = customToAny(a).rawType == customToAny(b).rawType

var x = Parent(x: 4)
var y = Child(x: 4, y:"Hello")
var z = Parent(x: 6)

echo compareRuntimeTypes(x, y)
echo compareRuntimeTypes(x, z)