Based on
https://github.com/ruby/ruby/blob/v2_1_0/doc/syntax/refinements.rdoc , there does not appear to be a way for a `require`d file to trigger `using` in the parent file:
Right now, each file in Rails core is responsible for loading the extensions it needs. It has no intention to push that to the caller, but it does because loading extensions has a global effect.
In the alternative approach with refinements, the (vague) idea would be the same, each file still loads the extensions it needs, the difference is precisely that it does not have a global side-effect.
By now we are talking about AS, and as a second iteration, Rails core (and all this is speculative at this point). We have not talked about Rails applications, which would still load all extensions unless the bare flag is true using the compatible behaviour that was outlined before.