Especially the errors related to traits are very difficult to me. Is there a trick? Will I get used to it? Or am I just a failure? :D

Like WTH is this?

the trait bound '(diesel::sql_types::Uuid, diesel::sql_types::Text, diesel::sql_types::Nullable, diesel::sql_types::Timestamp, diesel::sql_types::Timestamp): diesel::query_dsl::CompatibleType' is not satisfied the following other types implement trait 'diesel::query_dsl::CompatibleType': (ST0,) (ST0, ST1) (ST0, ST1, ST2) (ST0, ST1, ST2, ST3) (ST0, ST1, ST2, ST3, ST4) (ST0, ST1, ST2, ST3, ST4, ST5) (ST0, ST1, ST2, ST3, ST4, ST5, ST6) (ST0, ST1, ST2, ST3, ST4, ST5, ST6, ST7) and 24 others required for 'SelectStatement, DefaultSelectClause>, NoDistinctClause, ..., ..., ...>' to implement 'diesel_async::methods::LoadQuery<'_, _, models::Artist>

Or this:

the variant or associated item 'as_select' exists for enum 'Option<Image>', but its trait bounds were not satisfied the following trait bounds were not satisfied: 'std::option::Option<models::Image>: diesel::Selectable<_>' which is required by 'std::option::Option<models::Image>: diesel::SelectableHelper<_>' '&std::option::Option<models::Image>: diesel::Selectable<_>' which is required by '&std::option::Option<models::Image>: diesel::SelectableHelper<_>' '&mut std::option::Option<models::Image>: diesel::Selectable<_>' which is required by '&mut std::option::Option<models::Image>: diesel::SelectableHelper<_>'

or this:

the trait bound 'schema::image::columns::id: diesel::SelectableExpression<schema::artist::table>' is not satisfied the following other types implement trait 'diesel::SelectableExpression<QS>': <schema::image::columns::id as diesel::SelectableExpression<diesel::query_source::joins::Join<Left, Right, diesel::query_source::joins::Inner>>> <schema::image::columns::id as diesel::SelectableExpression<diesel::query_source::joins::Join<Left, Right, diesel::query_source::joins::LeftOuter>>> <schema::image::columns::id as diesel::SelectableExpression<schema::image::table>> <schema::image::columns::id as diesel::SelectableExpression<diesel::query_builder::SelectStatement<diesel::query_builder::FromClause<From>>>> <schema::image::columns::id as diesel::SelectableExpression<diesel::query_source::joins::JoinOn<Join, On>>> <schema::image::columns::id as diesel::SelectableExpression<diesel::query_builder::Only<schema::image::table>>> required for '(id, url, width, height, color, updated_at, created_at)' to implement 'diesel::SelectableExpression<schema::artist::table>' the full type name has been written to './target/debug/deps/server-25bcf4cf7c62d3bf.long-type-2030200755981097212.txt' 3 redundant requirements hidden required for '(diesel::expression::select_by::SelectBy<models::Artist, _>, diesel::expression::select_by::SelectBy<std::option::Option<models::Image>, _>)' to implement 'diesel::SelectableExpression<schema::artist::table>' required for 'SelectStatement<FromClause<table>, DefaultSelectClause<FromClause<table>>, NoDistinctClause, WhereClause<...>>' to implement 'diesel::query_dsl::methods::SelectDsl<(diesel::expression::select_by::SelectBy<models::Artist, _>, diesel::expression::select_by::SelectBy<std::option::Option<models::Image>, _>)>' the full type name has been written to './target/debug/deps/server-25bcf4cf7c62d3bf.long-type-3023492822805157679.txt'

    • BB_C@programming.dev
      3·
      1 year ago

      As I mentioned in my other comment, part of the problem is the list of implementers (which gets included as a suggestion) being too big, and maybe sometimes too complex.

      This is not inevitable and unescapable, as your comment may suggest. It is, in part, caused by the lack of (mature) support for some type system features, like HKTs.

      Luckily, this is not an inherent eternal limitation it Rust. Although, as I already mentioned, we are probably still years away from seeing this problem being fully in the past.