typeconstraint.scala

来自「JAVA 语言的函数式编程扩展」· SCALA 代码 · 共 31 行

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2006-2007, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

// $Id: TypeConstraint.scala 14416 2008-03-19 01:17:25Z mihaylov $


package scala

/** <p>
 *    A marker for annotations that, when applied to a type,
 *    should be treated as a constraint on the annotated type.
 *    A proper constraint should restrict the type based only
 *    on information mentioned within the type.  A Scala compiler
 *    can use this assumption to rewrite the contents of the
 *    constraint as necessary.  To contrast, a type annotation
 *    whose meaning depends on the context where it is written
 *    down is not a proper constrained type, and this marker
 *    should not be applied.  A Scala compiler will drop such
 *    annotations in cases where it would rewrite a type constraint.
 *  </p>
 *
 *  @author  Lex Spoon
 *  @version 1.1, 2007-11-5
 */
trait TypeConstraint extends Annotation