lib.rs

pub struct OutsideStruct<'a> {
    data: InsideStruct<'a>
}

pub struct InsideStruct<'a> {
    data: &'a[u8]
}

impl <'a>OutsideStruct<'a> {
    pub fn new<'b>(data:&'b[u8]) -> OutsideStruct<'b>{
        OutsideStruct{
            data: InsideStruct::new(data)
        }
    }
}

impl <'a>InsideStruct<'a> {
    pub fn new<'b>(data:&'b[u8]) -> InsideStruct{
        InsideStruct{
            data: data.clone()
        }
    }
}