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// check-pass
trait Document {
type Cursor<'a>: DocCursor<'a> where Self: 'a;
fn cursor(&self) -> Self::Cursor<'_>;
}
struct DocumentImpl {}
impl Document for DocumentImpl {
type Cursor<'a> = DocCursorImpl<'a>;
fn cursor(&self) -> Self::Cursor<'_> {
DocCursorImpl {
document: &self,
}
}
}
trait DocCursor<'a> {}
struct DocCursorImpl<'a> {
document: &'a DocumentImpl,
}
impl<'a> DocCursor<'a> for DocCursorImpl<'a> {}
struct Lexer<'d, Cursor>
where
Cursor: DocCursor<'d>,
{
cursor: Cursor,
_phantom: std::marker::PhantomData<&'d ()>,
}
impl<'d, Cursor> Lexer<'d, Cursor>
where
Cursor: DocCursor<'d>,
{
pub fn from<Doc>(document: &'d Doc) -> Lexer<'d, Cursor>
where
Doc: Document<Cursor<'d> = Cursor>,
{
Lexer {
cursor: document.cursor(),
_phantom: std::marker::PhantomData,
}
}
}
pub fn main() {
let doc = DocumentImpl {};
let lexer: Lexer<'_, DocCursorImpl<'_>> = Lexer::from(&doc);
}
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