Box
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.crClass Method Summary
- .box(object) : Pointer(Void)
Creates a Box for an object and returns it as a
Void*. - .new(object : T)
Creates a
Boxwith the given object- - .unbox(pointer : Pointer(Void)) : T
Unboxes a
Void*into an object of typeT.
Instance Method Summary
- #object : T
Returns the original object
Instance methods inherited from class Reference
==(other : self)==(other) ==, dup dup, hash hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference)
same?(other : Nil) same?, to_s(io : IO) : Nil to_s
Class methods inherited from class Reference
new new Instance methods inherited from class Object
!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)===(other : YAML::Any)
===(other) ===, =~(other) =~, class class, dup dup, hash hash, inspect(io : IO)
inspect inspect, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&block) tap, to_json(io : IO)
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(io : IO)
to_yaml to_yaml, try(&block) try
Class methods inherited from class Object
from_json(string_or_io, root : String) : selffrom_json(string_or_io) : self from_json, from_yaml(string_or_io) : self from_yaml
Class Method Detail
def self.new(object : T)Source
def self.unbox(pointer : Pointer(Void)) : TSource
Unboxes a Void* into an object of type T. Note that for this you must specify T: Box(T).unbox(data).
Instance Method Detail
def object : TSource
Returns the original object
© 2012–2017 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.22.0/Box.html
