class Box(T)

Overview

A Box allows turning any object to a Void* and back.

A Box's purpose is passing data to C as a Void* and then converting that back to the original data type.

For an example usage, see Proc's explanation about sending Procs to C.

Defined in:

box.cr

Class Method Summary

Instance Method Summary

Instance methods inherited from class Reference

==(other)
==(other : self)
==
, dup dup, hash hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, same?(other : Reference)
same?(other : Nil)
same?
, to_s(io : IO) : Nil to_s

Instance methods inherited from class Object

!=(other) !=, !~(other) !~, ==(other) ==, ===(other)
===(other : YAML::Any)
===(other : JSON::Any)
===
, =~(other) =~, class class, crystal_type_id crystal_type_id, dup dup, hash hash, inspect(io : IO)
inspect
inspect
, itself itself, not_nil! not_nil!, tap(&block) tap, to_json to_json, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ")
to_pretty_json
, to_s
to_s(io : IO)
to_s
, to_yaml
to_yaml(io : IO)
to_yaml
, try(&block) try

Class methods inherited from class Object

==(other : Class) ==, ===(other) ===, cast(other) : self cast, clone clone, dup dup, from_json(string_or_io) : self
from_json(string_or_io, root : String) : self
from_json
, from_yaml(string : String) : self from_yaml, hash hash, inspect(io) inspect, name : String name, nilable? nilable?, to_s(io) to_s, |(other : U.class) forall U |

Class Method Detail

def self.box(object) : Pointer(Void) #

Creates a Box for an object and returns it as a Void*.


[View source]
def self.new(object : T) #

Creates a Box with the given object.

This method isn't usually used directly. Instead, Box.box is used.


[View source]
def self.unbox(pointer : Pointer(Void)) : T #

Unboxes a Void* into an object of type T. Note that for this you must specify T: Box(T).unbox(data).


[View source]

Instance Method Detail

def object : T #

Returns the original object


[View source]