Often I have code where Option is used to indicate whether a value has been initialized or not. In these instances I often have code that either wants to use the value directly or initialize it and then use the value. So what I'm looking for is similar to as_ref()/as_mut() except they should return &T/&mut T respectively, and take either a value or a closure.

I think I would call the functions get{,_mut}_or_insert{,with}() marrying the get functions (for example in hashmaps) for getting references with the or_insert Entry like functions.