flatten calls to_ary on everything
I often ensure that I have an array by doing:
@foo = [x].flatten
But this has turned into a problem as of late, as it seems #flatten is calling #to_ary on every element in the array, and apparently catching the error raised if #to_ary isn't defined for that object. But that causes potential issues with objects that use #method_missing. I think #flatten should use
respond_to?(:to_ary) to make sure an object can handle it before actually calling it.