[Feature request] .apply()

[dev-ardi]

    fn apply<B, F>(self, f: F) -> Self
    where
        Self: Sized,
        F: FnMut(Self::Item),
    {
       f(self.item); // However this is done
        self
    }

Similar to foreach but doesn't consume the iterator. Equivalent to .map(|x| {[something with side effects]; x}) Useful for printing each element in the iterator for debugging, for example.

[Philippe-Cholet]

About the dbg PR alternative, I think about the inspect method: iter.inspect(|x| dbg!(x)).

If it's a method for our Itertools trait then what is .item?

If it's on each item like .map(|x| {[something with side effects]; x}), I think of our update adaptor: iter.update(|item/*: &mut Self::Item*/| ...).

Here, f takes ownership of the items. Should we clone them to return them anyway? Otherwise, there is for_each.

[scottmcm]

The signature as written can't work, since you're moving them item into the FnMut, which means it has to be map since there's no way to return the item afterwards.

I agree that this sounds like it's just inspect, where getting & not &mut is a feature.

[dev-ardi]

I agree