title: RxJava 2: Replacement for Subject<T,R>
body: <p>In RxJava 1.x it was possible to do a <code>T -&gt; R</code> conversion in a <code>Subject</code>. For example the input type could be a <code>Integer</code> and the output type could still be a <code>String</code>. In RxJava 2.0 this option has been removed, now it's just <code>Subject&lt;T&gt;</code> instead of <code>Subject&lt;T,R&gt;</code>. This change is also mentioned in the <a href="https://github.com/ReactiveX/RxJava/wiki/What&#39;s-different-in-2.0#subjects-and-processors" rel="nofollow noreferrer">What's different in 2.0</a> document on the RxJava wiki, but unfortunately no replacement is given. Is there any apart from declaring the <code>Subject</code> as <code>Subject&lt;Object&gt;</code>?</p>