generic updates with addition operator

[LolaLollipop]

i want to do a generic update but also use the addition operator (to increment), my code so far looks like:

fn increment<X>(user: i32, x: X) 
    where X: diesel::Insertable<crate::schema::members::table> + diesel::Expression + diesel::Column<Table = members::table>,
          X: diesel::expression::AsExpression<diesel::sql_types::Integer>,
          X::SqlType: diesel::sql_types::SqlType,
          X: diesel::ExpressionMethods,
          X: diesel::Expression<SqlType = diesel::sql_types::Integer>
{
    use crate::schema::members::user_id;
    use diesel::{ExpressionMethods, RunQueryDsl};   

    let mut conn = crate::get_connection();

    let _ = diesel::insert_into(members::table)
        .values((
            x.eq(1),
            user_id.eq(user),
        ))
        .on_conflict((user_id,))
        .do_update()
        .set((x.eq(x + 1),))
        .execute(&mut conn)?;
}

the problem is that it's erroring at the +, saying that i can't add an X to an {integer}. i've tried adding:

          X: std::ops::Add<i32>, 
          <X as std::ops::Add<i32>>::Output: diesel::Expression + diesel::expression::AsExpression<diesel::sql_types::Integer>,
          <<X as std::ops::Add<i32>>::Output as diesel::expression::AsExpression<diesel::sql_types::Integer>>::Expression: diesel::AppearsOnTable<members::table>,
          <X as std::ops::Add<i32>>::Output: diesel::AppearsOnTable<members::table>,

as a bound but this doesn't seem to work, and just generates a more complex issue.

what's the best way to write this so that i can increment it?

[weiznich]

I generally advice people not to try writing this kind of generic code for their applications as you end up with a pretty hard to maintain number of trait bounds if you get it to work. That's also the reason why I don't provide help figuring out these kind of trait bounds. Sorry, but you are on your own there if you want to truly go down that way.