feat: New array-style overloading

Step two didn't work so well, so this is actually step three. Avoids
  too much redundant type information.

src/util/overload.ts

@@ -0,0 +1,17 @@
+type UnionToIntersection<U> =
+    (U extends any ? (k: U) => void : never) extends ((k: infer I) => void)
+    ? I
+    : never;
+
+export default function overload<T extends readonly [...any[]]>(
+    imps: T): UnionToIntersection<T[number]> {
+    return <any>((...a: any[]) => {
+        for (let i = 0; i < imps.length; ++i) {
+            try {
+                const val = imps[i](...a)
+                return val
+            } catch {
+            }
+        }
+    })
+}