added unchecked.scala

1 files changed, 43 insertions, 0 deletions

diff --git a/src/library/scala/unchecked.scala b/src/library/scala/unchecked.scala
new file mode 100644
index 0000000000..488f1e4133
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+++ b/src/library/scala/unchecked.scala
@@ -0,0 +1,43 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2002-2007, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id: unsealed.scala 10201 2007-03-04 10:53:12 +0000 (Sun, 04 Mar 2007) mihaylov $
+
+
+package scala
+
+/** <p>
+ *    An annotation that gets applied to a selector in a match expression.
+ *    If it is present, exhaustiveness warnings for that expression will be
+ *    suppressed.
+ *  </p>
+ *  <p>
+ *    For example, compiling the code:
+ *  </p><pre>
+ *    <b>object</b> test <b>extends</b> Application {
+ *      <b>def</b> f(x: Option[int]) = x <b>match</b> {
+ *        <b>case</b> Some(y) => y
+ *      }
+ *      f(None)
+ *    }</pre>
+ *  <p>
+ *    will display the following warning:
+ *  </p><pre>
+ *    test.scala:2: warning: does not cover case {object None}
+ *      def f(x: Option[int]) = x match {
+ *                              ^
+ *    one warning found</pre>
+ *  <p>
+ *    The above message may be suppressed by substituting the expression
+ *    <code>x</code> with <code>(x: @unchecked)</code>. Then the
+ *    modified code will compile silently, but, in any case, a
+ *    <a href="MatchError.html"><code>MatchError</code></a>
+ *    will be raised at runtime.
+ *  </p>
+ */
+class unchecked extends Annotation {}