Ruby

It's a common idiom to use a fiber-local variable, but return a default value if it hasn't been assigned. Here's an example of Ruby code I would expect to be able to write:

def feature_enabled? Thread.current.fetch(:feature_enabled, true) end 

Unfortunately, Thread.current does not implement fetch, like Hash does. So I have to write the more verbose:

def feature_enabled? Thread.current.key?(:feature_enabled) ? Thread.current[:feature_enabled] : true end 

Thanks for your consideration!