Re:What Is Rust's Unsafe? (2019)
by zozbot234 on Sunday April 10, 2022 @02:55PM
(#30980441)
> Without those, without unsafe, shared borrow references would be true immutable borrow
Rust devs have thought about implementing "true immutable" before and found it to be problematic. It would come in quite handy for mostly anything related to FP or referential transparency/purity, but these things turn out to be very hard to reconcile with the "systems" orientation of Rust. Perhaps the answer will reside in some expanded notion of "equality" of values and objects, which might allow for trivial variation while verifying that the code you write respects the same notion of "equality".
Rust devs have thought about implementing "true immutable" before and found it to be problematic. It would come in quite handy for mostly anything related to FP or referential transparency/purity, but these things turn out to be very hard to reconcile with the "systems" orientation of Rust. Perhaps the answer will reside in some expanded notion of "equality" of values and objects, which might allow for trivial variation while verifying that the code you write respects the same notion of "equality".