Regime Semantics: from-let, from-mut, and from-proj

[FedericoBruzzone]

No description provided.

[Sbregiuz]

Some comments are reappliable to other lines with the same study case but with different data types in play

[Sbregiuz]

Shouldn't be allowed if the first proj is not used anymore until the second one is "deleted", or no more used?
Because something like:

fn f1(proj p : Point){
 &p.x += 2;
 f2(p);
}

fn f2(proj p: Point){
 &p.y += 3;
}

fn main(){
 let mut p : Point = Point{x : 1, y:2};
 fn1(&p);
}

Should be admissible in my opinion. (And I am changing regime from proj to proj)

[FedericoBruzzone]

Wow! Great point, you're right!
This should obviously be permissible: how could I not have thought of that?

This will, of course, help me clarify my thoughts on the proj regime.

[FedericoBruzzone]

Just let me clarify one point:

fn tmp(proj x: i32, proj y: i32) { x = &y; }
fn main() {
    let mut x: i32 = 1;
    let mut y: i32 = 2;
    tmp(&x, &y);
    // UB: x and y are mutable aliases of the same memory location
}

But we can prevent this!