javolution.io.Union Maven / Gradle / Ivy
/*
* Javolution - Java(TM) Solution for Real-Time and Embedded Systems
* Copyright (C) 2012 - Javolution (http://javolution.org/)
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software is
* freely granted, provided that this notice is preserved.
*/
package javolution.io;
/**
* Equivalent to C/C++ union; this class works in the same
* way as {@link Struct} (sub-class) except that all members are mapped
* to the same location in memory.
* Here is an example of C union:
* [code]
* union Number {
* int asInt;
* float asFloat;
* char asString[12];
* };[/code]
* And its Java equivalent:
* [code]
* public class Number extends Union {
* Signed32 asInt = new Signed32();
* Float32 asFloat = new Float32();
* Utf8String asString = new Utf8String(12);
* }[/code]
* As for any {@link Struct}, fields are directly accessible:
* [code]
* Number num = new Number();
* num.asInt.set(23);
* num.asString.set("23"); // Null terminated (C compatible)
* float f = num.asFloat.get();[/code]
*
* @author Jean-Marie Dautelle
* @version 1.0, October 4, 2004
*/
public abstract class Union extends Struct {
/**
* Default constructor.
*/
public Union() {}
/**
* Returns true.
*
* @return true
*/
public final boolean isUnion() {
return true;
}
}