type Player = { Name: string; Score: int; Id: System.Guid }

​

type PlayerDTO = 

  { Name: string; Score: int; Id: string }

  with static member op_Implicit(p: Player) : PlayerDTO = 

      { Name = p.Name; Score = p.Score; Id = p.Id.ToString() }

let p: Player = { Name = "Yan"; Score = 42; Id = System.Guid.NewGuid() }

let dto = PlayerDTO.op_Implicit(p)

​

printfn "%A" p

printfn "%A" dto