Notes/notes-service/vendor/bitvec/doc/ptr/proxy.md

Proxy Bit-References

Rust does not permit the use of custom proxy structures in place of true reference primitives, so APIs that specify references (like IndexMut or DerefMut) cannot be implemented by types that cannot manifest &mut references directly. Since bitvec cannot produce an &mut bool reference within a BitSlice, it instead uses the BitRef proxy type defined in this module to provide reference-like work generally, and simply does not define IndexMut<usize>.