title: CompletableFuture from Callable?
body: <p>Today I experimented with the "new" <code>CompletableFuture</code> from Java 8 and found myself confused when I didn't find a <code>runAsync(Callable)</code> method.
  I can do it myself like shown below, but why is this (to me very obvious and useful utility method) missing? Am <i>I</i> missing something?</p>
  
  <pre class="lang-java prettyprint-override"><code>public static &lt;T&gt; CompletableFuture&lt;T&gt; asFuture(Callable&lt;? extends T&gt; callable, Executor executor) {
      CompletableFuture&lt;T&gt; future = new CompletableFuture&lt;&gt;();
      executor.execute(() -&gt; {
          try {
              future.complete(callable.call());
          } catch (Throwable t) {
              future.completeExceptionally(t);
          }
      });
      return future;
  }</code></pre>