Merge #7297 #7338

7297: Propose trait associated items and autoimport traits on completion r=matklad a=SomeoneToIgnore

![trait_imports](https://user-images.githubusercontent.com/2690773/104819998-6faeb480-583a-11eb-8b45-b7351b51b90e.gif)

Closes #7248

7338: Parse `impl const Trait` r=Veykril a=Veykril

Closes #7313

bors r+

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/ide/src/doc_links.rs

@@ -438,10 +438,10 @@ fn get_symbol_fragment(db: &dyn HirDatabase, field_or_assoc: &FieldOrAssocItem)
         FieldOrAssocItem::Field(field) => format!("#structfield.{}", field.name(db)),
         FieldOrAssocItem::AssocItem(assoc) => match assoc {
             AssocItem::Function(function) => {
-                let is_trait_method = matches!(
-                    function.as_assoc_item(db).map(|assoc| assoc.container(db)),
-                    Some(AssocItemContainer::Trait(..))
-                );
+                let is_trait_method = function
+                    .as_assoc_item(db)
+                    .and_then(|assoc| assoc.containing_trait(db))
+                    .is_some();
                 // This distinction may get more complicated when specialization is available.
                 // Rustdoc makes this decision based on whether a method 'has defaultness'.
                 // Currently this is only the case for provided trait methods.

crates/ide/src/lib.rs

@@ -478,6 +478,7 @@ impl Analysis {
         position: FilePosition,
         full_import_path: &str,
         imported_name: String,
+        import_for_trait_assoc_item: bool,
     ) -> Cancelable<Vec<TextEdit>> {
         Ok(self
             .with_db(|db| {
@@ -487,6 +488,7 @@ impl Analysis {
                     position,
                     full_import_path,
                     imported_name,
+                    import_for_trait_assoc_item,
                 )
             })?
             .unwrap_or_default())