README.md

Design Patterns - Elements of Reusable Object-Oriented Software

Introduction

This is my implementation of the Design Patterns from the book

'Design Patterns: Elements of Reusable Object-Oriented Software'
Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides
ISBN 0-201-63361-2
Copyright 1995
21th Printing, November 2000

The webpage and official 'code' for this book were previously available from

1. http://st-www.cs.illinois.edu/users/patterns/DPBook/DPBook.html
2. http://st-www.cs.illinois.edu/patterns/dpbook/Source.html

Unfortunately, these links no longer work. Someone pointed me to https://github.com/willis7/DPCPP as an alternative, but I don't know if the code in this repository is an exact copy of the original code. In any case, if anybody knows the new location of the 'official' source code for the book, please let me know!

The nice thing about the Design Patterns book is that it is... well... not complete :-) To come to a complete working implementation of all the Design Patterns presented in the book and be able to play with them, requires some extra coding. The goal of this project is to actually provide the missing pieces and come to something that will compile and run cleanly.

On the following websites, I have found C++ code that helped me complete everything:

• http://www.c-jump.com/CIS75/Week11/
• http://www.c-jump.com/Download/Patterns/Prototype/html/
• https://code.google.com/p/basic-algorithm-operations/source/browse/trunk/DP
• http://dislab.hufs.ac.kr/wiki/Lecture/Design_Pattern
• http://blog.csdn.net/joey_zoy/article/details/5610810
• https://github.com/wangqiang8511/C---Design-Patterns-Examples/

And here are some interesting slides that give some more explanation:

• http://www.cs.toronto.edu/~penny/teaching/csc407/

A more modern C++11 approach using Boost libraries was given in a talk by Tobias Darm given here:

• http://www.infoq.com/presentations/gof-patterns-c-plus-plus-boost

An interview from 2009 with the GoF authors is given here:

• http://www.informit.com/articles/article.aspx?p=1404056

A dependency analysis and refactoring of the Gang of Four examples can be found at

• https://github.com/zebmason/GoFRefactored/blob/master/README.md

Feel free to send me your comments, suggestions and improvements in the form of a git pull request!

Building

To build everything, you need at least the following:

• CMake 3.14 or higher

Checkout the code into a Design-Patterns-GoF directory:

~$ git checkout [email protected]:BartVandewoestyne/Design-Patterns-GoF.git

Then, switch to the Design-Patterns-GoF directory and do the build:

~$ cd Design-Patterns-GoF
~/Design-Patterns-GoF$ cmake -S . -B build
~/Design-Patterns-GoF$ cmake --build build

You can also use CMake's -j N option for parallel builds on N cores and -v for verbose builds:

~/Design-Patterns-GoF$ cmake --build build -j 4 -v

Branches

This repository has two branches:

• The master branch has the code as it is given in the book plus extra code to make it compile and run. All code that is in the book should be an exact subset of the code in the master branch, without any modifications. If you spot differences, please let me know.
• The book's code also has its flaws as can be seen when enabling compiler warnings and using static code analysis tools. The gof_improved branch is exactly the same as the master branch, except that several code issues are fixed or improved, following best practices and always adhering the C++98 standard (which was the current standard at the time the book was written). To see what fixes and improvements were applied, you can compare the two branches.