♻️ Share the Matchable universe between both matchers

src/primitive-union.ts

@@ -2,6 +2,7 @@ import type { Exact } from "type-fest";
 
 import type {
     HandlerMap,
+    Matchable,
     PatternKey,
     PatternParam,
     PatternReturns,
@@ -9,10 +10,6 @@ import type {
     UnaryFn,
 } from "./matcher-shared.ts";
 
-// The primitive universe a matcher can discriminate. `boolean` is admitted as
-// the pair `true | false`; see README § Caveats for the unsupported members.
-type Matchable = string | number | boolean | null | undefined;
-
 type Handlers<T extends Matchable, R> = {
     [K in PatternKey<T>]: UnaryFn<PatternParam<K>, R>;
 };