Open Is Good: Fast, Orthogonal Open (Multi) Methods with YOMM2 :: Jean-Louis Leroy скачать в хорошем качестве

Open Is Good: Fast, Orthogonal Open (Multi) Methods with YOMM2 :: Jean-Louis Leroy

Presented at the Core C++ 2024 conference, Tel Aviv. Have you ever felt your life would be simpler if you could just add virtual functions to a class hierarchy whenever you needed to (e.g., to persist an object or render it in JSON), but refrained because you did not own the classes, and doing so would violate the principle of separation of concerns? Have you toiled on a Visitor class again? Did you struggle to get double dispatch right because you needed to implement binary operations for polymorphic classes? Open methods solve all these problems, while requiring you to write much less code -- and they deliver superior performance. Open methods are virtual functions that are defined outside of a class. Given a method declaration and a set of specializations, the most specific version is selected, depending on the dynamic type of one or more arguments. Open methods make it possible to add polymorphic behavior to existing class hierarchies, without modifying them. open methods offer a superior alternative to the Visitor pattern, and a solution to the problem of cross-cutting concerns. Since more than one argument can participate in the selection of the specialization, open methods also solve the binary (or multiple) dispatch problem. YOMM2 is an implementation of open methods in library. It was inspired by the paper Open Multi-Methods for C++, by Peter Pirkelbauer, and Yuriy Solodkyy, and Bjarne Stroustrup. YOMM2 delivers excellent performance, and requires no external tooling. It was first released in 2017 and presented at CppCon 2018. Since then, the library has evolved significantly. Support was added for friend and member methods, templatized methods, automatic deduction of inheritance graphs, wide pointers for faster dispatch, support for custom RTTI, static offsets for faster-than-virtual method dispatch, etc. YOMM2 is available on GitHub and on Compiler Explorer. ----- Jean-Louis Leroy is a Senior Software Engineer at Bloomberg in New York City. He has a long-standing interest in extensible languages, from Forth (a long time ago) through Lisp, Perl, D, Python and C++. In addition to his personal open source project YOMM2, he is also part of the engineering team that created and published BlazingMQ, an open source distributed message queueing system.