Scala视图界定

 package big.data.analyse.dataSet

 /**
   * 视图界定
   * Created by zhen on 2018/11/29.
   */
 /*class Pair_NotPerfect[T <: Comparable[T]](val first:T, val second:T){ //泛型
   def bigger = if(first.compareTo(second) > 0)first else second
 }*/
 class Pair_NotPerfect[T <% Comparable[T]](val first:T, val second:T){ //视图界定，支持隐式转换
   def bigger = if(first.compareTo(second) > 0) first else second
 }

 class Pair_Better[T <% Ordered[T]](val first:T, val second:T){ //视图界定，支持隐式转换，支持操作符
   def bigger = if(first > second) first else second
 }

 object Bound {
   def main(args: Array[String]) {
     val pair = new Pair_NotPerfect("Spark", "Hadoop")
     println(pair.bigger)

     val pairInt = new Pair_NotPerfect(3, 5)
     println(pairInt.bigger)

     val pair_Better = new Pair_Better("Solr", "Python")
     println(pair_Better.bigger)
   }
 }

结果：