// MIR for `mapped` after PreCodegen

fn mapped(_1: impl Iterator<Item = T>, _2: impl Fn(T) -> U) -> () {
    debug iter => _1;
    debug f => _2;
    let mut _0: ();
    let mut _3: std::iter::Map<impl Iterator<Item = T>, impl Fn(T) -> U>;
    let mut _4: std::iter::Map<impl Iterator<Item = T>, impl Fn(T) -> U>;
    let mut _12: std::option::Option<U>;
    let _14: ();
    let mut _15: &mut std::iter::Map<impl Iterator<Item = T>, impl Fn(T) -> U>;
    scope 1 {
        debug iter => _4;
        let _13: U;
        scope 2 {
            debug x => _13;
        }
        scope 4 (inlined <Map<impl Iterator<Item = T>, impl Fn(T) -> U> as Iterator>::next) {
            debug self => _15;
            let mut _5: &mut impl Iterator<Item = T>;
            let mut _6: std::option::Option<T>;
            let mut _7: &mut impl Fn(T) -> U;
            scope 5 (inlined Option::<T>::map::<U, &mut impl Fn(T) -> U>) {
                debug self => _6;
                debug f => _7;
                let mut _8: isize;
                let _9: T;
                let mut _10: (T,);
                let mut _11: U;
                scope 6 {
                    debug x => _9;
                    scope 7 (inlined ops::function::impls::<impl FnOnce<(T,)> for &mut impl Fn(T) -> U>::call_once) {
                        debug self => _7;
                        debug args => _10;
                    }
                }
            }
        }
    }
    scope 3 (inlined <Map<impl Iterator<Item = T>, impl Fn(T) -> U> as IntoIterator>::into_iter) {
        debug self => _3;
    }

    bb0: {
        _3 = <impl Iterator<Item = T> as Iterator>::map::<U, impl Fn(T) -> U>(move _1, move _2) -> [return: bb1, unwind continue];
    }

    bb1: {
        StorageLive(_4);
        _4 = copy _3;
        goto -> bb2;
    }

    bb2: {
        StorageLive(_12);
        // DBG: _15 = &_4;
        StorageLive(_7);
        StorageLive(_6);
        StorageLive(_5);
        _5 = &mut (_4.0: impl Iterator<Item = T>);
        _6 = <impl Iterator<Item = T> as Iterator>::next(move _5) -> [return: bb3, unwind: bb10];
    }

    bb3: {
        StorageDead(_5);
        _7 = &mut (_4.1: impl Fn(T) -> U);
        StorageLive(_8);
        StorageLive(_9);
        _8 = discriminant(_6);
        switchInt(move _8) -> [0: bb4, 1: bb6, otherwise: bb9];
    }

    bb4: {
        StorageDead(_9);
        StorageDead(_8);
        StorageDead(_6);
        StorageDead(_7);
        StorageDead(_12);
        drop(_4) -> [return: bb5, unwind continue];
    }

    bb5: {
        StorageDead(_4);
        return;
    }

    bb6: {
        _9 = move ((_6 as Some).0: T);
        StorageLive(_11);
        StorageLive(_10);
        _10 = (copy _9,);
        _11 = <impl Fn(T) -> U as FnMut<(T,)>>::call_mut(move _7, move _10) -> [return: bb7, unwind: bb10];
    }

    bb7: {
        StorageDead(_10);
        _12 = Option::<U>::Some(move _11);
        StorageDead(_11);
        StorageDead(_9);
        StorageDead(_8);
        StorageDead(_6);
        StorageDead(_7);
        _13 = move ((_12 as Some).0: U);
        _14 = opaque::<U>(move _13) -> [return: bb8, unwind: bb10];
    }

    bb8: {
        StorageDead(_12);
        goto -> bb2;
    }

    bb9: {
        unreachable;
    }

    bb10 (cleanup): {
        drop(_4) -> [return: bb11, unwind terminate(cleanup)];
    }

    bb11 (cleanup): {
        resume;
    }
}