*scratch*

(defmacro let-into [to & bindings]
  `(let [~@bindings]
     (into ~to ~(vec (for [sym (take-nth 2 bindings)]
                       [(keyword sym) sym])))))

(comment
  (let-into {}
    x 1
    y (inc x)
    z (inc y))

  expands to:
  (let [x 1
        y (inc x)
        z (inc y)]
    (into {} [[:x x] [:y y] [:z z]]))

  returning:
  {:x 1 :y 2 :z 3}

  with (defrecord Foo [x y]) we get:
  (let-into (Foo. 0 0)
    x 1
    y (inc x))

  but having to supply a dummy instance is ugly...)