java-design-patterns/twin/README.md

---
title: Twin
category: Structural
language: en
tags:
 - Extensibility
---

## Intent
Twin pattern is a design pattern which provides a standard solution to simulate multiple
inheritance in java

## Class diagram
![alt text](./etc/twin.png "Twin")

## Applicability
Use the Twin idiom when

* To simulate multiple inheritance in a language that does not support this feature.
* To avoid certain problems of multiple inheritance such as name clashes.

## Credits

* [Twin – A Design Pattern for Modeling Multiple Inheritance](http://www.ssw.uni-linz.ac.at/Research/Papers/Moe99/Paper.pdf)
-												implements Twin design pattern #63

											
										
										
											2015-11-14 17:38:35 +08:00
+								---
 								title: Twin
-												Update frontmatters

											
										
										
											2021-09-12 13:27:23 +03:00
+								category: Structural
-												fix: Fixed pages showing up in wrong language (#1752)

* Fix languages

* Missed change for version number

* Add language field for presentation

* Revert change in README for double buffer

Co-authored-by: Jackie Nim <=>
											
										
										
											2021-05-19 10:49:05 -06:00
+								language: en
-												Categorize and tag all patterns #213

											
										
										
											2015-12-28 15:52:44 +02:00
+								tags:
-												https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags

											
										
										
											2019-12-13 21:09:28 +02:00
+								 - Extensibility
-												implements Twin design pattern #63

											
										
										
											2015-11-14 17:38:35 +08:00
+								---
-												Use headings instead of bold text in index.md #238

											
										
										
											2016-01-03 21:14:30 +01:00
+								## Intent
-												https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags

											
										
										
											2019-12-13 21:09:28 +02:00
+								Twin pattern is a design pattern which provides a standard solution to simulate multiple
-												implements Twin design pattern #63

											
										
										
											2015-11-14 17:38:35 +08:00
+								inheritance in java
-												#1113 Link uml-reverse-mapper created class diagrams to readme, where needed

											
										
										
											2019-12-07 20:01:13 +02:00
+								## Class diagram
-												implements Twin design pattern #63

											
										
										
											2015-11-14 17:38:35 +08:00
+								![alt text](./etc/twin.png "Twin")
-												Use headings instead of bold text in index.md #238

											
										
										
											2016-01-03 21:14:30 +01:00
+								## Applicability
 								Use the Twin idiom when
-												implements Twin design pattern #63

											
										
										
											2015-11-14 17:38:35 +08:00
-												https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags

											
										
										
											2019-12-13 21:09:28 +02:00
+								* To simulate multiple inheritance in a language that does not support this feature.
 								* To avoid certain problems of multiple inheritance such as name clashes.
-												implements Twin design pattern #63, add credit and rephrase the comments

											
										
										
											2015-11-16 10:01:03 +08:00
-												Use headings instead of bold text in index.md #238

											
										
										
											2016-01-03 21:14:30 +01:00
+								## Credits
-												implements Twin design pattern #63, add credit and rephrase the comments

											
										
										
											2015-11-16 10:01:03 +08:00
-												Categorize and tag all patterns #213

											
										
										
											2015-12-28 15:52:44 +02:00
+								* [Twin – A Design Pattern for Modeling Multiple Inheritance](http://www.ssw.uni-linz.ac.at/Research/Papers/Moe99/Paper.pdf)