Do not allow memoization methods with nonzero arity

[mbj]

This makes sure the memoizer is not used to create tricky to track down
bugs.

Currently adamantium allows the following:

class Foo
  include Adamantium

  def something(x)
    x * 2
  end
  memoize :something
end

foo = Foo.new
foo.something(1) # => 2
foo.something(2) # => 2, Tricky to track down bug.

[mbj]

@dkubb Any problems with this? I'd like to get it merged.

[dkubb]

You could also write this as if method.arity.nonzero? which matches what you're testing a bit more closely.

[dkubb]

Also, since you're only using method one time I would be more likely just to do it inline, eg:

if instance_method(method_name).arity.nonzero?
  # ...

EDIT: oh wait, I see what you're doing now. nevermind. Does UnboundMethod#name always know the original name?

[mbj]

Yeah, it does always return the original name. https://github.com/rubyspec/rubyspec/blob/master/core/unboundmethod/name_spec.rb

[dkubb]

@mbj I think you can merge this in if you change to use Numeric#nonzero? like I suggested.

[mbj]

CI failed for external and IMHO temporal reason on one ruby https://travis-ci.org/dkubb/adamantium/builds/4056359 I'll merge anyways. This will trigger a new build that I predict to be green.

[dkubb]

@mbj when a single build fails you can always restart it by clicking on the icon in the upper-right that looks like a little gear.. click on "Restart Job".

[mbj]

Thx. Im not a great GUI user ;). BTW I plan to add a rake task to devtools for this job. (Or a CLI task)