Global SingletonSemaphore=CreateSemaphore(1)

Interface OO_Interface    ; Interface for any value of this type
  Get.i()
  Set(Value.i)
  Destroy()
EndInterface

Structure OO_Structure ; The *VTable structure
  Get.i
  Set.i
  Destroy.i
EndStructure

Structure OO_Var
  *VirtualTable.OO_Structure
  Value.i
EndStructure

Procedure OO_Get(*Self.OO_Var)
  ProcedureReturn *Self\Value
EndProcedure

Procedure OO_Set(*Self.OO_Var, n)
  *Self\Value = n
EndProcedure

Procedure CreateSingleton()
  If TrySemaphore(SingletonSemaphore)
    *p.OO_Var = AllocateMemory(SizeOf(OO_Var))
    If *p
      *p\VirtualTable = ?VTable
    EndIf
  EndIf
  ProcedureReturn *p
EndProcedure

Procedure OO_Destroy(*Self.OO_Var)
  FreeMemory(*Self)
  SignalSemaphore(SingletonSemaphore)
EndProcedure

DataSection
  VTable:
  Data.i @OO_Get()
  Data.i @OO_Set()
  Data.i @OO_Destroy()
EndDataSection