///////// third lib /////////////
struct ThirdPartPage<'a> {
    name: &'a str,
    content: &'a str
}

struct ThirdPartDoc<'a> {
    page: ThirdPartPage<'a>
}

impl <'a> ThirdPartDoc<'a> {
    fn get_page(&self) -> &ThirdPartPage<'a> {
        &self.page
    }
}

///////// resource //////////


trait ResourceTrait<'a> {
    fn get_content(&self) -> &str;
}

struct TirdpartResource<'a> {
    data: &'a ThirdPartPage<'a>
}

impl<'a> ResourceTrait<'a> for TirdpartResource<'a> {
    fn get_content(&self) -> &str {
        self.data.content
    }
}

////////// main logic ////////

struct Owner<'a> {
    doc: Option<ThirdPartDoc<'a>>
}

impl<'a> Owner<'a> {
    fn get_resource(&self) -> Option<Box<dyn ResourceTrait<'a>>> {
        match &self.doc {
            Some(doc) => {
                Some(Box::new(TirdpartResource {
                    data: doc.get_page()
                }))
            },
            None => Option::None
        }
    }
}

fn main() {
    let owner = Owner {
        doc: Some(ThirdPartDoc {
            page: ThirdPartPage {
                name: "page",
                content: "content"
            }
        })
    };
    
    let res = owner.get_resource();
    
    println!("{}", res.unwrap().get_content());
}

third lib是外部库，这里是错误信息：

   Compiling playground v0.0.1 (/playground)
error[E0495]: cannot infer an appropriate lifetime for borrow expression due to conflicting requirements
  --> src/main.rs:42:15
   |
42 |         match &self.doc {
   |               ^^^^^^^^^
   |
note: first, the lifetime cannot outlive the anonymous lifetime defined on the method body at 41:21...
  --> src/main.rs:41:21
   |
41 |     fn get_resource(&self) -> Option<Box<dyn ResourceTrait<'a>>> {
   |                     ^^^^^
note: ...so that reference does not outlive borrowed content
  --> src/main.rs:42:15
   |
42 |         match &self.doc {
   |               ^^^^^^^^^
note: but, the lifetime must be valid for the lifetime `'a` as defined on the impl at 40:6...
  --> src/main.rs:40:6
   |
40 | impl<'a> Owner<'a> {
   |      ^^
note: ...so that the types are compatible
  --> src/main.rs:44:22
   |
44 |                   Some(Box::new(TirdpartResource {
   |  ______________________^
45 | |                     data: doc.get_page()
46 | |                 }))
   | |__________________^
   = note: expected `ResourceTrait<'a>`
              found `ResourceTrait<'_>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0495`.
error: could not compile `playground`

To learn more, run the command again with --verbose.