Earlier quoted context omitted.
> This might just be a case of needing non-lexical lifetimes. I'm not sure about that, because I don't know the details of what issues you ran into. I don't think the issue is about lexical lifetimes, but I don't have a very good understanding of what that means, either. My issue is that I frequently want to take some data and pass it into two separate functions, but I can't do this unless those functions are designe…
> Even if those values contain owned references into the heap, the programs can be trivially proven to be correct. I don't think that's true. Passing data to a function when it's not a reference means that you're giving ownership to that function. How could you then pass it to another function (unless the first returned it again)? Once a function has ownership, it means nothing else has ownership of the data. Basical…
Only in Rust, but there's no apparent reason to move ownership. If Rust didn't move ownership during pass-by-value, it would still be trivial to prove the following code correct:
fn main() {
let x = String::new();
foo(x);
bar(x);
// x is destroyed
}
Here's the equivalent in C++:
int main() {
std::string x = "";
foo(x);
bar(x);
// x is destroyed
}