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

Instance methods inherited from class Object

! !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other) ===, =~(other) =~, class class, clone clone, crystal_type_id crystal_type_id, dup dup, hash hash, inspect
inspect(io : IO)
inspect
, itself itself, not_nil! not_nil!, tap(&block) tap, to_json to_json, to_pretty_json(io : IO)
to_pretty_json
to_pretty_json
, to_s
to_s(io : IO)
to_s
, to_yaml(io : IO)
to_yaml
to_yaml
, try(&block) try

Class methods inherited from class Object

==(other : Class) ==, ===(other) ===, cast(other) : self cast, from_json(string_or_io) from_json, from_yaml(string : String) from_yaml, hash hash, inspect(io) inspect, name : String name, to_s(io) to_s

Class Method Detail

def self.box(object) #

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


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def self.unbox(pointer : Pointer(Void)) #

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


[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.


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Instance Method Detail

def object #

Returns the original object


[View source]