Borrowing issues with attempted caching

Question

The following code snippet does the same things in 3 ways.

use std::collections::HashMap;

struct Foo {
    cache: HashMap,
}

impl Foo         


        

Answer 1

You could try to add &mut on self on show_impl as in

...
fn show_impl(&self, what: &String)  
...

So it won't get mixed.