| (**************************************************************************) |
(* Mini, a type inference engine based on constraint solving. *)
(* Copyright (C) 2006. François Pottier, Yann Régis-Gianas *)
(* and Didier Rémy. *)
(* *)
(* This program is free software; you can redistribute it and/or modify *)
(* it under the terms of the GNU General Public License as published by *)
(* the Free Software Foundation; version 2 of the License. *)
(* *)
(* This program is distributed in the hope that it will be useful, but *)
(* WITHOUT ANY WARRANTY; without even the implied warranty of *)
(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *)
(* General Public License for more details. *)
(* *)
(* You should have received a copy of the GNU General Public License *)
(* along with this program; if not, write to the Free Software *)
(* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA *)
(* 02110-1301 USA *)
(* *)
| (**************************************************************************) |
(* $Id $*)
| (** This module implements a very simple notion of ``mark''. A mark is really a reference cell (without content). Creating a new mark requires allocating a new cell, and comparing marks requires comparing pointers. *) |
type t =
unit ref
let fresh =
ref
let same =
(==)
let none =
fresh()