Another "does not live long enough"


Example code

I know that A is the top level struct and Some will be valid through the life of A, and therefore putting references of Some inside _T_s should be ok. How do I do that, how do I avoid “does not live long enough” error? Is it event possible in safe Rust, or is it the “disallowed self referencing non-movable struct” thing?


Yeah, it’s that.


Safe Rust does not allow a struct to contain a reference to itself.

If you really need self-references:

  • Wrap them in Rc<Some>
  • Use raw/unsafe pointer *const Some. Be careful not to move the struct, e.g. use Box::new(A) before getting the address.

Also consider another design:

  • Store an integer index to a Vec instead of a real reference.
  • Hold the Vec outside the struct (internal references to a borrowed slice are OK, since they all point outside the struct)