utoipa: Generics do not work with lifetime specifiers

Hey @juhaku

Thank you for your work on this library. It is astonishing and a great developer experience. However, I have a use-case where the behavior is a bit shakey.

I have a rocket web api for testing out some scenarios. One scenario would be to return paginated generic responses.

I have the following struct that returns a generic list of data, with a total sice and two optional links to the “next” or “prev” page.

/// Paginated response for a list of results.
/// Contains optional links to the next and previous page,
/// and the total count of items that are available.
#[derive(Debug, Serialize, ToSchema)]
pub struct Paginated<'r, TResult> {
    pub total: usize,
    pub data: Vec<TResult>,
    pub next: Option<&'r str>,
    pub prev: Option<&'r str>,
}

I know referenced the crate via git reference on the master branch to get the new features like “content” in the responses for multiple response types. Then I tried to use the aliases, however, they do not work since I don’t have all the structs in one file.

When trying with type aliases like so:

type Test = Paginated<'static, Test<'static>>;

#[derive(OpenApi)]
// components(schemas(test::models::Test, test::models::Metadata)),
#[openapi(
    paths(test::get_all, test::get_by_id),
    components(schemas(Test))
)]
pub(super) struct ApiDoc;

I run into the following error:

Could not resolve reference: Could not resolve pointer: /components/schemas/TResult does not exist in document

With aliases, the references to the models are not present, in which case the compiler will not run through.

Do you have any advice or solution for this matter? When using aliases like described (#[aliases(PaginatedPages = Paginated<Page>)]) it requires a “,” in between. Or when I specify the lifetimes, it complains that the combination is not correct for parsing.

Regards