Previously, trying to run multiple queries on one Master struct did not compile, as the previous query moved the struct and destroyed it. All other query-able structs derived Copy, so this previously wasn't a problem, but Master can't as it contains non-copyable data.
This is great! It's exactly the change I would have made and the commit message is superb; you even precisely stated how it got to this state (the Copyable structs). I'm super impressed!
Previously, trying to run multiple queries on one Master struct did not compile, as the previous query moved the struct and destroyed it. All other query-able structs derived Copy, so this previously wasn't a problem, but Master can't as it contains non-copyable data.