How to SELECT * (SELECT *) ?

[JadKHaddad]

Currently I could write this statement like this

  let inner = Query::select().column(Asterisk).to_owned();

  let outer = Query::select()
      .column(Asterisk)
      .expr_as(
          Expr::cust(format!("({})", inner.to_string(PostgresQueryBuilder))),
          Alias::new("inner"),
      )
      .to_owned();

But it feels wrong to use format! with manual parentheses placement.

Any better way to do this?

A more technical question would be: How to use a SelectStatement as an Expr?