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POJava annotations: at variable initialization, but not assignment?
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  1. POJava annotations: at variable initialization, but not assignment?
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    copied!<p>I've been having trouble understanding where exactly an annotation has to or can be placed.</p> <p>The class with this method compiles, but gives a warning "unchecked":</p> <pre><code>&lt;B extends BitSet&gt; void doStuff(LinkedList&lt;B&gt; list) { B board = list.getFirst(); B cloneBoard; cloneBoard = (B) board.clone(); //unchecked } </code></pre> <p>This compiles without warning:</p> <pre><code>&lt;B extends BitSet&gt; void doStuff(LinkedList&lt;B&gt; list) { B board = list.getFirst(); @SuppressWarnings("unchecked") B cloneBoard = (B) board.clone(); } </code></pre> <p>This doesn't compile but marks cloneBoard with an error:</p> <pre><code>&lt;B extends BitSet&gt; void doStuff(LinkedList&lt;B&gt; list) { B board = list.getFirst(); B cloneBoard; @SuppressWarnings("unchecked") cloneBoard = (B) board.clone(); // cloneBoard cannot be resolved to a type; // VariableDeclaratorID expected } </code></pre> <p>In the Sun tutorial on annotations, I couldn't find an answer as to why this is: <a href="http://docs.oracle.com/javase/tutorial/java/javaOO/annotations.html" rel="nofollow">http://docs.oracle.com/javase/tutorial/java/javaOO/annotations.html</a>.</p> <p>The grammar definition didn't help me either, since I'm not quite sure I understand it correctly: <a href="http://java.sun.com/docs/books/jls/third_edition/html/syntax.html#18.1" rel="nofollow">http://java.sun.com/docs/books/jls/third_edition/html/syntax.html#18.1</a></p> <p>It seems to me that what's the problem here is that annotations can be specifically used for variables, but only when they are declared; any later assignment will not be covered by the annotation. Is this correct? Is there a more elegant solution than suppressing unchecked warnings for the whole method?</p>
 

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