Best introduction to C++ template metaprogramming?
C++TemplatesMetaprogrammingC++ Problem Overview
Static metaprogramming (aka "template metaprogramming") is a great C++ technique that allows the execution of programs at compile-time. A light bulb went off in my head as soon as I read this canonical metaprogramming example:
#include <iostream>
using namespace std;
template< int n >
struct factorial { enum { ret = factorial< n - 1 >::ret * n }; };
template<>
struct factorial< 0 > { enum { ret = 1 }; };
int main() {
cout << "7! = " << factorial< 7 >::ret << endl; // 5040
return 0;
}
If one wants to learn more about C++ static metaprogramming, what are the best sources (books, websites, on-line courseware, whatever)?
C++ Solutions
Solution 1 - C++
[Answering my own question]
The best introductions I've found so far are chapter 10, "Static Metaprogramming in C++" from Generative Programming, Methods, Tools, and Applications by Krzysztof Czarnecki and Ulrich W. Eisenecker, ISBN-13: 9780201309775; and chapter 17, "Metaprograms" of C++ Templates: The Complete Guide by David Vandevoorder and Nicolai M. Josuttis, ISBN-13: 9780201734843.
Todd Veldhuizen has an excellent tutorial here.
A good resource for C++ programming in general is Modern C++ Design by Andrei Alexandrescu, ISBN-13: 9780201704310. This book mixes a bit of metaprogramming with other template techniques. For metaprogramming in particular, see sections 2.1 "Compile-Time Assertions", 2.4 "Mapping Integral Constants to Types", 2.6 "Type Selection", 2.7 "Detecting Convertibility and Inheritance at Compile Time", 2.9 "NullType and EmptyType" and 2.10 "Type Traits".
The best intermediate/advanced resource I've found is C++ Template Metaprogramming by David Abrahams and Aleksey Gurtovoy, ISBN-13: 9780321227256
If you'd prefer just one book, get C++ Templates: The Complete Guide since it is also the definitive reference for templates in general.
Solution 2 - C++
Andrei Alexandrescu's Modern C++ Design book covers a lot of this and other tricks for speedy and efficient modern C++ code and is the basis for the Loki library.
Also worth mentioning is the Boost libraries, which heavily use these techniques and are usually of very high quality to learn from (although some are quite dense).
Solution 3 - C++
Modern C++ Design, a brilliant book and design pattern framework by Alexandrescu. Word of warning, after reading this book I stopped doing C++ and thought "What the heck, I can just pick a better language and get it for free".
Solution 4 - C++
Two good books that spring to mind are:
- Modern C++ Design / Andrei Alexandrescu (It's actually 7 years old despite the name!)
- C++ Templates: The Complete Guide / Vandevoorde & Josuttis
It's quite an in-depth field, so a good book like one of these is definitely recommended over websites. Some of the more advanced techniques will have you studying the code for some time to figure out how they work!
Solution 5 - C++
Modern C++ is one of the best introductions I've read. It covers actual useful examples of template metaprogramming. Also take a look at the companion library Loki.
Solution 6 - C++
There won't be a large list of books, as the list of people with a lot of experience is limited. Template metaprogramming started for real around the first C++ Template Programming Workshop in 2000, and many of the authors named so far attended. (IIRC, Andrei didn't.) These pioneers greatly influenced the field, and basically what should be written is now written. Personally, I'd advice Vandevoorde & Josuttis. Alexandrescu's is a tough book if you're new to the field.
Solution 7 - C++
google Alexandrescu, Modern C++ Design: Generic Programming and Design Patterns Applied
Solution 8 - C++
Veldhuizen's original papers were good. If you up for a whole book, then there's Vandevoorde's book "C++ Templates Complete Guide". And when you're ready for the master's course, try Alexandrescu's Modern C++ Design.