Looking for a specific example explaining lifetime and reborrowing

help
1

Hi all,

last week I have encoutered an amazing example explaining lifetime and reborrowing.
I didn't save the page, and been searching it ever since without success. I am not sure if this is in this forum, stack overflow, or any other online article.

The structure of the example was something like this:

fn foo()
{
    let mut x = 3;
    let rx = &mut x; 
    {
        some code
        some code
    }
    some code // line 1
    some code // line 2
}

Now, the cool part was that when including the block bracket '{', '}', only line 1 compiles and line 2 raises a compilation error. And when commenting out the block brackets (and keeping all other code, including the code in the block, as is), only line 2 compiles and line 1 raises an error.

It was an amazing example showcasing lifetime and reborrowing, but for the life of me I coulnd't find it again. I tried using AI to generate the code or to find the link, but no luck so far.

// case 1
fn foo()
{
    let mut x = 3;
    let rx = &mut x; 
    {
        some code
        some code
    }
    some code // line 1
    //some code ==> line 2 : error
}

// case 2
fn foo()
{
    let mut x = 3;
    let rx = &mut x; 
    //{
        some code
        some code
    //}
    //some code ==> line 1 : error
    some code // line 2 
}

Does someone recognize this example?
Thanks