Lax compiler causes problem with Result[] object encapsulating base of inherited object

[mjfh]

The following program compiles and runs ok.

import
  results, unittest2

type
  ARef = ref AObj
  AObj = object of RootObj

  BRef = ref BObj
  BObj = object of AObj

# Statement compiles all right and runs ok
discard Result[ARef,void].ok(BRef())
discard Result[void,ARef].err(BRef())

# Statements compile all right 
expect ObjectAssignmentDefect:
  # Will throw a run-time exception
  discard Result[AObj,void].ok(BObj())

expect ObjectAssignmentDefect:
  # Will throw a run-time exception
  discard Result[void,AObj].err(BObj())

The problem is that the Result[] clause does not work properly when encapsulating the base object AObj while given some inherited object BObj. But the compiler accepts that construction as valid.

[arnetheduck]

This is what the language works like (ie it has got nothing to do with Result):

type
  AObj = object of RootObj
  BObj = object of AObj

var x: AObj
x = BObj() # Raises ObjectAssignmentDefect