package b0

  1. Overview
  2. Docs
Software construction and deployment kit

Install 

dune-project
 Dependency

erratique.ch Readme Changelog ISC; BSD-2-Clause License Edit opam file Versions (2)

Authors

  1. T
    The b0 programmers

Maintainers

  1. Daniel Bünzli

Sources

b0-0.0.6.tbz
sha512=e9aa779e66c08fc763019f16d4706f465d16c05d6400b58fbd0313317ef33ddea51952e2b058db28e65f7ddb7012f328c8bf02d8f1da17bb543348541a2587f0

doc/src/b0.std/b0__type.ml.html

Source file b0__type.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
(*---------------------------------------------------------------------------
   Copyright (c) 2025 The more programmers. All rights reserved.
   SPDX-License-Identifier: ISC
  ---------------------------------------------------------------------------*)


(* See http://alan.petitepomme.net/cwn/2015.03.24.html#1
   In the stdlib since 5.1. *)

type ('a, 'b) eq = Equal : ('a, 'a) eq

module Id = struct
  type _ id = ..
  module type ID = sig
    type t
    type _ id += Id : t id
  end

  type 'a t = (module ID with type t = 'a)

  let make (type a) () : a t =
    (module struct type t = a type _ id += Id : t id end)

  let provably_equal
      (type a b) ((module A) : a t) ((module B) : b t) : (a, b) eq option
    =
    match A.Id with B.Id -> Some Equal | _ -> None

  let uid (type a) ((module A) : a t) =
    Obj.Extension_constructor.id (Obj.Extension_constructor.of_val A.Id)
end