style: some small fixes

- remove invalid struct pattern
lint message: struct pattern is not needed for a unit variant
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#unneeded_struct_pattern
- remove call to default() on unit struct
lint message: use of `default` to create a unit struct
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#default_constructed_unit_structs
- replace if/else by direct affectation
lint message: this if-then-else expression assigns a bool literal
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#needless_bool_assign
- replace assert_eq on unit by `unwrap` + let typed binding

src/db/test.rs

@@ -21,7 +21,7 @@ fn test_suite(db: Db) {
 	let res = db.transaction::<_, (), _>(|tx| {
 		assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), va);
 
-		assert_eq!(tx.insert(&tree, ka, vb).unwrap(), ());
+		let _: () = tx.insert(&tree, ka, vb).unwrap();
 
 		assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vb);
 
@@ -33,7 +33,7 @@ fn test_suite(db: Db) {
 	let res = db.transaction::<(), _, _>(|tx| {
 		assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vb);
 
-		assert_eq!(tx.insert(&tree, ka, vc).unwrap(), ());
+		let _: () = tx.insert(&tree, ka, vc).unwrap();
 
 		assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vc);