Trait RightJoinKey 

pub trait RightJoinKey<RK, RV, JK>:
    Send
    + Sync
    + 'static {
    const OPTIONAL: bool;

    // Required method
    fn right_join_key(&self, row_key: &RK, row_value: &RV) -> Option<JK>;
}

Extracts a right-side join key while making key absence explicit.

The adapter types below avoid overlapping blanket implementations for required keys and Option keys. Join runtimes monomorphize this call, so RequiredRightKey retains the ordinary infallible fast path.

Required Associated Constants

const OPTIONAL: bool

Whether extraction can omit a row. Used to preserve the required-key fast path.

Required Methods

fn right_join_key(&self, row_key: &RK, row_value: &RV) -> Option<JK>

Returns the join key, or None when the row has no relationship.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<RK, RV, JK, F> RightJoinKey<RK, RV, JK> for OptionalRightKey<F>

where F: Fn(&RK, &RV) -> Option<JK> + Send + Sync + 'static,

const OPTIONAL: bool = true

impl<RK, RV, JK, F> RightJoinKey<RK, RV, JK> for RequiredRightKey<F>

where F: Fn(&RK, &RV) -> JK + Send + Sync + 'static,

const OPTIONAL: bool = false