# Module Gpointer

    module Gpointer: sig .. end

`Gpointer`: various kinds of pointers to C data

    type 'a optaddr

Marked pointers

    val optaddr : 'a option -> 'a optaddr

    type boxed

Boxed pointers

    val boxed_null : boxed

    val peek_string : ?pos:int -> ?len:int -> boxed -> string

    val peek_int : boxed -> int

    val poke_int : boxed -> int -> unit

    val peek_nativeint : boxed -> nativeint

    val poke_nativeint : boxed -> nativeint -> unit

    type 'a optboxed

    val optboxed : 'a option -> 'a optboxed

    val may_box : f:('a -> 'b) -> 'a option -> 'b optboxed

    type [>  ] variant_table

Variant tables

    val decode_variant : ([>  ] as 'a) variant_table -> int -> 'a

    val encode_variant : ([>  ] as 'a) variant_table -> 'a -> int

    val decode_flags : ([>  ] as 'a) variant_table -> int -> 'a list

    val encode_flags : ([>  ] as 'a) variant_table -> 'a list -> int

    exception Null

Null pointer exception

    type 'a stable

Ensure a value is copied in the old generation

    val stable_copy : 'a -> 'a stable

Region handling

    type region

The abstract type of heap regions

    val length : region -> int

the length of the region

    val get_addr : region -> nativeint

the start address of the region

    val sub : ?pos:int -> ?len:int -> region -> region

subregion of length `len` starting at offset `pos`

    val get_byte : region -> pos:int -> int

    val set_byte : region -> pos:int -> int -> unit

    val blit : src:region -> dst:region -> unit

    val region_of_bytes : bytes -> region

create a region sharing a string

    val bytes_of_region : region -> bytes

copy the contents of the region to a string

    type 'a bigarray = (int, Stdlib.Bigarray.int8_unsigned_elt, 'a) Stdlib.Bigarray.Array1.t

    val region_of_bigarray : 'a bigarray -> region

create a region sharing a bigarray

Unsafe access

    val unsafe_create_region : path:int array -> get_length:('a -> int) -> 'a -> region

`unsafe_create_region ~path ~get_length` returns a function to build regions from a specific kind of data abstraction

    val unsafe_get_byte : region -> pos:int -> int

    val unsafe_set_byte : region -> pos:int -> int -> unit