From 013dcf08a1c7256243273c7e48c6ff80b02cfb02 Mon Sep 17 00:00:00 2001 From: marcandre Date: Tue, 24 Oct 2017 18:08:00 +0000 Subject: lib/weakref: Remove incorrect example [DOC] [Bug #14031] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60404 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- lib/weakref.rb | 47 ----------------------------------------------- 1 file changed, 47 deletions(-) (limited to 'lib/weakref.rb') diff --git a/lib/weakref.rb b/lib/weakref.rb index c88babba46..824d4016e1 100644 --- a/lib/weakref.rb +++ b/lib/weakref.rb @@ -15,53 +15,6 @@ require "delegate" # GC.start # start the garbage collector # p foo.to_s # should raise exception (recycled) # -# == Example -# -# With help from WeakRef, we can implement our own rudimentary WeakHash class. -# -# We will call it WeakHash, since it's really just a Hash except all of it's -# keys and values can be garbage collected. -# -# require 'weakref' -# -# class WeakHash < Hash -# def []= key, obj -# super WeakRef.new(key), WeakRef.new(obj) -# end -# end -# -# This is just a simple implementation, we've opened the Hash class and changed -# Hash#store to create a new WeakRef object with +key+ and +obj+ parameters -# before passing them as our key-value pair to the hash. -# -# With this you will have to limit your self to String keys, otherwise you -# will get an ArgumentError because WeakRef cannot create a finalizer for a -# Symbol. Symbols are immutable and cannot be garbage collected. -# -# Let's see it in action: -# -# omg = "lol" -# c = WeakHash.new -# c['foo'] = "bar" -# c['baz'] = Object.new -# c['qux'] = omg -# puts c.inspect -# #=> {"foo"=>"bar", "baz"=>#, "qux"=>"lol"} -# -# # Now run the garbage collector -# GC.start -# c['foo'] #=> nil -# c['baz'] #=> nil -# c['qux'] #=> nil -# omg #=> "lol" -# -# puts c.inspect -# #=> WeakRef::RefError: Invalid Reference - probably recycled -# -# You can see the local variable +omg+ stayed, although its reference in our -# hash object was garbage collected, along with the rest of the keys and -# values. Also, when we tried to inspect our hash, we got a WeakRef::RefError. -# This is because these objects were also garbage collected. class WeakRef < Delegator -- cgit v1.2.3