// 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 _5: &mut std::iter::Map<impl Iterator<Item = T>, impl Fn(T) -> U>;
    let mut _6: std::option::Option<U>;
    let mut _7: isize;
    let _9: ();
    scope 1 {
        debug iter => _4;
        let _8: U;
        scope 2 {
            debug x => _8;
        }
    }
    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 = move _3;
        goto -> bb2;
    }

    bb2: {
        StorageLive(_6);
        StorageLive(_5);
        _5 = &mut _4;
        _6 = <Map<impl Iterator<Item = T>, impl Fn(T) -> U> as Iterator>::next(move _5) -> [return: bb3, unwind: bb9];
    }

    bb3: {
        StorageDead(_5);
        _7 = discriminant(_6);
        switchInt(move _7) -> [0: bb4, 1: bb6, otherwise: bb8];
    }

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

    bb5: {
        StorageDead(_4);
        return;
    }

    bb6: {
        _8 = move ((_6 as Some).0: U);
        _9 = opaque::<U>(move _8) -> [return: bb7, unwind: bb9];
    }

    bb7: {
        StorageDead(_6);
        goto -> bb2;
    }

    bb8: {
        unreachable;
    }

    bb9 (cleanup): {
        drop(_4) -> [return: bb10, unwind terminate(cleanup)];
    }

    bb10 (cleanup): {
        resume;
    }
}