Function signature_help_for_tuple_pat_ish 

fn signature_help_for_tuple_pat_ish<'db>(
    db: &'db RootDatabase,
    res: SignatureHelp,
    pat: &SyntaxNode,
    token: SyntaxToken,
    field_pats: AstChildren<Pat>,
    fields: impl ExactSizeIterator<Item = Type<'db>>,
    display_target: DisplayTarget,
) -> SignatureHelp