Trouble with lifetimes

I have the following struct in one of the crates that I’m using.

pub struct Set<'a, 'b: 'a, 'c: 'a + 'b> {
    sockets: ManagedSlice<'a, Option<Item<'b, 'c>>>

impl<'a, 'b: 'a, 'c: 'a + 'b> Set<'a, 'b, 'c> {
    pub fn new<SocketsT>(sockets: SocketsT) -> Set<'a, 'b, 'c>
            where SocketsT: Into<ManagedSlice<'a, Option<Item<'b, 'c>>>> {
        let sockets = sockets.into();
        Set {
            sockets: sockets

I need to have struct Set as one of the fields in another struct. For example,

pub struct foo {

impl foo {
        pub fn init(&mut self){
            self.sockets = Set::new(vec![]);

But this results in the following error.

21 |     sockets:Set,
   |             ^^^^^^^^^ expected 3 lifetime parameters

I read about advance lifetimes in rust, but could not figure out how to work this out. How to correctly set the lifetimes here?

You would need to declare the lifetimes in the foo struct declaration and then use them in the sockets field declaration. Unless you intend to/can use 'static for all 3 lifetime parameters.

I’m unclear on how to declare life times in the foo struct (not the syntax). I tried different ways of declaring them but they did not work. I would like to know the thinking pattern on how to do it.

If they’re all generic, then it’ll be essentially a repeat of what’s in Set itself:

struct foo<'a, 'b: 'a, 'c: 'a + 'b> {
   sockets: Set<'a, 'b, 'c>,

What did you try that didn’t work?

I managed to get it to work using 'static for all lifetime parameters. The above code resulted in a compiler error where it complained that it could not infer lifetime of c.