pub trait DieselReserveSpecialization { }
Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Expand description

This is a marker trait which indicates that diesel may specialize a certain QueryFragment impl in a later version. If you as a user encounter, where rustc suggests adding this a bound to a type implementing Backend consider adding the following bound instead YourQueryType: QueryFragment<DB> (the concrete bound is likely mentioned by rustc as part of a note: …

For any user implementing a custom backend: You likely want to implement this trait for your custom backend type to opt in the existing QueryFragment impls in diesel. As indicated by the i-implement-a-third-party-backend-and-opt-into-breaking-changes feature diesel reserves the right to specialize any generic QueryFragment impl via SqlDialect in a later minor version release