Compiling day23-unstable_diffusion v0.1.0 (/usr/home/burnus/advent_of_code_2022/day23-unstable_diffusion) error[E0308]: mismatched types --> src/main.rs:130:46 | 130 | elfs.iter_mut().for_each(|elf| elf = &elf.consider(round, grid)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability | = note: expected mutable reference `&mut Elf` found reference `&Elf` error[E0308]: mismatched types --> src/main.rs:131:46 | 131 | elfs.iter_mut().for_each(|elf| elf = &elf.reposition(grid)); | ^^^^^^^^^^^^^^^^^^^^^ types differ in mutability | = note: expected mutable reference `&mut Elf` found reference `&Elf` For more information about this error, try `rustc --explain E0308`. error: could not compile `day23-unstable_diffusion` due to 2 previous errors