# Module Bool

    module Bool: sig .. end

Boolean values.

- Since 4.08

## Booleans

    type t = bool =

`|` | `false`
`|` | `true`

The type of booleans (truth values).

The constructors `false` and `true` are included here so that they have paths, but they are not intended to be used in user-defined data types.

    val not : bool -> bool

`not b` is the boolean negation of `b`.

    val (&&) : bool -> bool -> bool

`e0 && e1` is the lazy boolean conjunction of expressions `e0` and `e1`. If `e0` evaluates to `false`, `e1` is not evaluated. Right-associative operator at precedence level 3/11.

    val (||) : bool -> bool -> bool

`e0 || e1` is the lazy boolean disjunction of expressions `e0` and `e1`. If `e0` evaluates to `true`, `e1` is not evaluated. Right-associative operator at precedence level 2/11.

## Predicates and comparisons

    val equal : bool -> bool -> bool

`equal b0 b1` is `true` if and only if `b0` and `b1` are both `true` or both `false`.

    val compare : bool -> bool -> int

`compare b0 b1` is a total order on boolean values. `false` is smaller than `true`.

## Converting

    val to_int : bool -> int

`to_int b` is `0` if `b` is `false` and `1` if `b` is `true`.

    val to_float : bool -> float

`to_float b` is `0.` if `b` is `false` and `1.` if `b` is `true`.

    val to_string : bool -> string

`to_string b` is `"true"` if `b` is `true` and `"false"` if `b` is `false`.

    val seeded_hash : int -> bool -> int

A seeded hash function for booleans, with the same output value as `Hashtbl.seeded_hash`. This function allows this module to be passed as argument to the functor `Hashtbl.MakeSeeded`.

- Since 5.1

    val hash : bool -> int

An unseeded hash function for booleans, with the same output value as `Hashtbl.hash`. This function allows this module to be passed as argument to the functor `Hashtbl.Make`.

- Since 5.1