Request: map_ok equivalent for Options/map_some

[dialectician4]

map_ok has been excellent for mapping over Result::Ok's in an iter. I've recently been working on an iter chain which hits an Option at a certain point leading to:

.map(...)
.map(|opt_t1| opt_t1.map(|t1| {
...
}))
.map(|opt_t2| opt_t2.map(|t2| {
...
}))

Since map_ok exists for results, I thought an equivalent map_some would be very useful to get the equivalent code:

.map(...)
.map_some(|t1| ...)
.map_some(|t2| ...)

If this seems reasonable, I'd be very happy to raise a PR to implement!

[scottmcm]

Can you show more about the specific case you're using? ? can often do really well here...