In ruby you can throw a rescue at the end of an assignment to catch any errors that might come up. I have a function (below: a_function_that_may_fail) where it's convenient to let it throw an error if certain conditions aren't met. The following code works well

post = {}
# Other Hash stuff
post['Caption'] = a_function_that_may_fail rescue nil

However I'd like to have post['Caption'] not even set if the function fails.

I know I can do:

begin
  post['Caption'] = a_function_that_may_fail
recsue
end

but that feels a little excessive - is there a simpler solution?