Split your data and methods into smaller components, then you can take disjoint borrows to various components on self: fn fetch_access_token(_base_url: &str) -> String { String::new() } fn get_env_url() -> String { String::new() } #[derive(Default)] struct BaseUrl(Option<String>); impl BaseUrl { fn get(&mut self) -> &str { self.0.get_or_insert_with(|| get_env_url()) } } #[derive(Default)] struct App { base_url: … Read more
I believe the confusion is because you’re conflating names with storage. fn main() { let x = 5; // x_0 println!(“The value of x is {}”, x); let x = 6; // x_1 println!(“The value of x is {}”, x); } In this example, there is one name (x), and two storage locations (x_0 and … Read more
Usually the borrow checker can distinguish between the different fields of a structure, but this doesn’t work within closures (lambdas). Instead, borrow the second field outside the closure: let field2 = &strct.field2; strct.field1.retain(|v| !field2.contains(v));
First a pointed to the string “Dog”. Then you changed the variable a to point at a new string “Dog eats treats”. You didn’t actually mutate the string “Dog”. Strings are immutable, variables can point at whatever they want.
You can create a new struct similar to the Ref<‘a,T> guard returned by RefCell::borrow(), in order to wrap this Ref and avoid having it going out of scope, like this: use std::cell::Ref; struct FooGuard<‘a> { guard: Ref<‘a, MutableInterior>, } then, you can implement the Deref trait for it, so that it can be used as … Read more