tests/ui/codegen/box-deref-segfault-misopt.rs

//! Regression test for <https://github.com/rust-lang/rust/issues/30081>.
//! Misoptimization caused this to segfault.
//@ run-pass

pub enum Instruction {
    Increment(i8),
    Loop(Box<Box<()>>),
}

fn main() {
    let instrs: Option<(u8, Box<Instruction>)> = None;
    instrs.into_iter()
        .map(|(_, instr)| instr)
        .map(|instr| match *instr { _other => {} })
        .last();
}