Method insert

datafusion/optimizer/src/join_key_set.rs:60–67

Insert the join key `(left = right)` into the set if join pair `(right = left)` is not already in the set returns true if the pair was inserted

(&mut self, left: &Expr, right: &Expr)

    ///
    /// returns true if the pair was inserted
    pub fn insert(&mut self, left: &Expr, right: &Expr) -> bool {
        if self.contains(left, right) {
            false
        } else {
            self.inner.insert((left.clone(), right.clone()));
            true
        }
    }

    /// Same as [`Self::insert`] but avoids cloning expression if they
    /// are owned