News

There Is A New Future -- Felix Petriconi

Version 1.0 of a new C++ future and channel library has been released.

There Is A New Future

by Sean Parent, Foster Brereton and Felix Petriconi

About the library:

This library provides high level abstractions for implementing algorithms that eases the use of multiple CPU cores while minimizing the contention.

The future implementaton differs in several aspects compared to the C++11/14/17 standard futures: It provides continuations and joins, which were just added in a C++17 TS. But more important this futures propagate values through the graph and not futures. This allows an easy way of creating splits. That means a single future can have multiple continuations into different directions. An other important difference is that the futures support cancellation. So if one is not anymore interested in the result of a future, then one can destroy the future without the need to wait until the future is fullfilled, as it is the case with std::future (and boost::future). An already started future will run until its end, but will not trigger any continuation. So in all these cases, all chained continuations will never be triggered. Additionally the future interface is designed in a way, that one can use build in or custom build executors.

Since one can create with futures only graphs for single use, this library provides as well channels. With these channels one can build graphs, that can be used for multiple invocations.

CppCast Episode 104: Postmodern C++ with Tony Van Eerd

Episode 104 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Tony Van Eerd to talk about his recent award winning C++Now talk on Postmodern C++ and his views on lock-free programming.

CppCast Episode 104: Postmodern C++ with Tony Van Eerd

by Rob Irving and Jason Turner

About the interviewee:

Tony Van Eerd has been coding for well over 25 years, and hopefully coding well for some of that. Mostly in graphics/video/film/broadcast (at Inscriber & Adobe), writing low level pixel++, high level UI, threading, and everything else. He now enables painting with light at Christie Digital. He is on the C++ Committee. He is a Ninja and a Jedi.

CppCon 2016: STL Algorithms - why you should use them, and how to write your own--Marshall Clow

Have you registered for CppCon 2017 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2016 for you to enjoy. Here is today’s feature:

STL Algorithms - why you should use them, and how to write your own

by Marshall Clow

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

One of the most powerful features of the C++ standard library is the collection of basic algorithms. Everyone knows about sort and copy, but there are is a lot of powerful capabilities in the other algorithms as well. In this talk, I will explore some of the algorithms in the library, and give a rationale for writing your own, along with examples.

The motivation for writing your own algorithms is that you can create generic building blocks that can be used over and over again in your library or application, and which will allow your to program at a higher level of abstraction. Instead of thinking, "how do I sort this vector", you just call std::sort. The same should apply to the algorithms that are specific to your domain - once you write them.

CppCon 2016: High Performance Code 201: Hybrid Data Structures--Chandler Carruth

Have you registered for CppCon 2017 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2016 for you to enjoy. Here is today’s feature:

High Performance Code 201: Hybrid Data Structures

by Chandler Carruth

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Modern programs’ performance characteristics are often dictated by their data. Whether the cache locality of data access, the size of working set, or avoiding costly memory allocation overhead. Unfortunately, the standard C++ library data structures range from adequate to terrible at controlling these aspects, and they don’t provide any of the core mechanisms needed for extremely efficient data structure design.

This talk will present the core concepts of designing high performance data structures in C++. It is based on years of experience in the LLVM compiler as well as several other large code bases. From these principles, the talk will propose a suite of data structures that provide performance without loss of generality or functionality. As much as this talk will present specific data structure designs, its primary intent will be to give an understanding of what makes these structures have greater performance than more naive approaches.

Quick Q: When is an rvalue evaluated?

Quick A: When it is assigned.

Recently on SO:

When is an rvalue evaluated?

s2 binds to the expression s1 + s1, but is this evaluated at the time s2 is assigned

Yes.

And also would s2 hold memory for a temporary string?

Precisely, s2 is bound to a temporary std::string.

s1 + s1 will produce a temporary std::string, which will be bound to the reference s2 (and its lifetime is extended to the lifetime of the reference). Then s2 += "Test";, performs operator+=() on  s2, i.e. the temporary std::string.

CppCon 2016: Garbage In, Garbage Out: Arguing about Undefined Behavior...--Chandler Carruth

Have you registered for CppCon 2017 in September? Don’t delay – Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2016 for you to enjoy. Here is today’s feature:

Garbage In, Garbage Out: Arguing about Undefined Behavior...

by Chandler Carruth

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

There has been an overwhelming amount of tension in the programming world over the last year due to something that has become an expletive, a cursed and despised term, both obscene and profane: **undefined behavior**. All too often, this issue and the discussions surrounding it descend into unproductive territory without actually resolving anything.

In this talk, I'm going to try something very bold. I will try to utterly and completely do away with the use of the term "undefined behavior" in these discussions. And I will unquestionably fail. But in the process of failing, I will outline a framework for understanding the actual root issues that the software industry faces here, and try to give constructive and clear paths forward, both for programmers and the programming language.

And, with luck, I will avoid being joined on stage by any unruly nasal demons.

CppCast Episode 103: Travis CI with Richel Bilderbeek

Episode 103 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Richel Bilderbeek to talk about the benefits of using Travis CI for C++ developers and the role of C++ in theoretical biology.

CppCast Episode 103: Travis CI with Richel Bilderbeek

by Rob Irving and Jason Turner

About the interviewee:

Richel Bilderbeek is a C++ developer for 17 years. He is mostly interested in what the literature has to say about good C++ practices, then teaching children and to adults, additionally writing articles, blog posts and tutorials. In his professional life, he is a PhD in theoretical biology.