@Mara I like this idea, helps with what feels like gymnastics in several situations. Especially helps as a learning opportunity on temporary lifetime extension to help demystify rust. A natural extension would be for function bodies to use "super let", so that `pin!` could be a [safe] function. I hit this problem much more often than the nested blocks in your exposition. Though that sounds like an advanced form of "placement" so there might be a lot wrapped into there. But it would be good to consider how this feature may evolve longer term such as for those use cases. Syntactically I think the use of "super" here is clever in a good way — an alternative syntax might involve explicit lifetimes but any options that come to my mind there feel needlessly verbose.