Capture mutable and immutable reference at the same time with different lifetimes

help
1

I'm still learning Rust. Now I tried to create some sort of restricted LinkedList using lifetimes.
To accomplish what I wanted to do I had to split up my insert method:

pub fn insert1<'lifetime_node>(&self, node: &'lifetime_node mut ListNode<'lifetime_list, T>) -> () 
{
	node.next = self.next;
}
	
pub fn insert2(&mut self, node: &'lifetime_list ListNode<'lifetime_list, T>) -> () 
{
	self.next = Option::<&Self>::Some(node);
}

Is there a way to put both into one function while keeping the mutable reference only for as long as the function call but the immutable reference for longer?

2

No there isn’t, and the impossibility of expressing such borrowing patterns indeed is a known limitation of Rust function signatures.

The best you can do is let it stay two separate function calls, and possibly bundle them up with a macro.

1 Like
3

eye-roll

Okay thanks for your fast reply. I'm gonna add that to my list of stuff I'd attempt to optimize in Rust language.