rust/library/core
León Orell Valerian Liehr ab9e0a72ef
Rollup merge of #125043 - RalfJung:ref-type-safety-invariant, r=scottmcm
reference type safety invariant docs: clarification

The old text could have been read as saying that you can call a function if these requirements are upheld, which is definitely not true as they are an underapproximation of the actual safety invariant.

I removed the part about functions relaxing the requirements via their documentation... this seems incoherent with saying that it may actually be unsound to ever temporarily violate the requirement. Furthermore, a function *cannot* just relax this for its return value, that would in general be unsound. And the part about "unsafe code in a safe function may assume these invariants are ensured of arguments passed by the caller" also interacts with relaxing things: clearly, if the invariant has been relaxed, unsafe code cannot rely on it any more. There may be a place to give general guidance on what kinds of function contracts can exist, but the reference type is definitely not the right place to write that down.

I also took a clarification from https://github.com/rust-lang/rust/pull/121965 that is orthogonal to the rest of that PR.

Cc ```@joshlf``` ```@scottmcm```
2024-05-22 23:41:11 +02:00
..
benches Add benchmarks for impl Debug for str 2024-05-01 09:54:29 +02:00
src Rollup merge of #125043 - RalfJung:ref-type-safety-invariant, r=scottmcm 2024-05-22 23:41:11 +02:00
tests Rename flatten(_mut)as_flattened(_mut) 2024-05-15 23:39:33 -07:00
Cargo.toml Add opt-for-size core lib feature flag 2024-05-11 14:07:19 +02:00