Defining "setter" methods within a trait.

RustQuestion5.rs

// The example below gives the following:
//
// "error: cannot borrow `*self` as mutable more than once at a time"
//
// I understand why, but I am wondering if it is possible to define
// "setter" methods within the trait in a way similar to this?

#[deriving(Show)]
pub struct MyStruct<'a> { i: int, j: int }

pub trait A<'a> {
    fn get_mystruct(&'a mut self) -> &'a mut MyStruct;
    fn set_with_i(&'a mut self, i: int) {
        self.get_mystruct().i = i;      
        self.get_mystruct().j = i*2;    // "error: cannot borrow `*self` as mutable more than once at a time"
    }
    fn set_with_j(&'a mut self, j: int) {
        self.get_mystruct().j = j;      
        self.get_mystruct().j = j/2;    // "error: cannot borrow `*self` as mutable more than once at a time"
    }
}

impl<'a> A<'a> for MyStruct<'a> {
    fn get_mystruct(&'a mut self) -> &'a mut MyStruct { self }
}

SOLVED! By removing the lifetimes from the setter function arguments and adding a lifetime parameter to get_mystruct.