By Blog Staff | Jun 3, 2014 05:39 AM | Tags: None
Overload 121 is now available. It contains the following C++-related articles, and more:
CONSTANTS often shout. Jonathan Wakely considers why this happens in C and what the alternatives are in C++.
Using multiple interfaces can slow things down. Daniel Gutson and Pablo Oliva present an alternative.
By Blog Staff | Jun 3, 2014 05:28 AM | Tags: None
Hot off the Channel 9 video press from last week's Lang.NEXT conference:
Lang.NEXT Keynote: What – if anything – have we learned from C++?
by Bjarne Stroustrup
What is the essence of C++? Why did it succeed despite its well-understood flaws? What lessons -- if any -- can be applied to newer languages?
Themes: Social and technical factors. Resource management. Generic programming. The importance of being inefficient. The importance of syntax. How (not) to specify a language. Standardization and compatibility. And no, I don't plan to condemn C++ -- it is still the best language around for a lot of things, and getting better. It just isn't anywhere near perfect (even of its kind) or the best at everything -- and was never claimed to be.
By Blog Staff | Jun 2, 2014 08:40 AM | Tags: None
More CppCon 2014 accepted talks have just been announced, below. For past announcements about the conference program, see also CppCon Program Preview, 1 of N and CppCon 2104: Initial Partial Topics and Speakers.
Super Early Bird registration has sold out, but Early Bird registration is available until June 30.
CppCon Program Preview, 2 of N
by Boris Kolpackov
From the announcement:
Continuing with the program preview, the next set of accepted talks is below (summary first, abstracts following):
- Andrei Alexandrescu: “Mo’ Hustle Mo’ Problems”
- Andrew Sutton: “Generic Programming with Concepts Lite”
- Marshall Clow: “Hardening Your Code”
- Nate Kohl: “cppreference.com: Documenting C++ One Edit at a Time”
- Kate Gregory, James McNellis: “Modernizing Legacy C++ Code”
Andrei Alexandrescu: “Mo’ Hustle Mo’ Problems"
Reasonably-written C++ code will be naturally fast. This is due to C++’s excellent low-penalty abstractions and a memory model close to the machine. However, a large category of applications have no boundaries on desired speed, meaning there’s no point of diminishing returns in making code faster. Better speed means less power consumed for the same work, more workload with the same data center expense, better features for the end user, more features for machine learning, better analytics, and more. Optimizing has always been an art, and in particular optimizing C++ on contemporary hardware has become a task of formidable complexity. This is because modern hardware has a few peculiarities about it that are not sufficiently understood and explored. This talk discusses a few such effects, and guides the attendee on how to navigate design and implementation options in search for better performance.
Speaker’s bio: Andrei Alexandrescu is a researcher, software engineer, and author. He wrote three best-selling books on programming (Modern C++ Design, C++ Coding Standards, and The D Programming Language) and numerous articles and papers on wide-ranging topics from programming to language design to Machine Learning to Natural Language Processing. Andrei holds a PhD in Computer Science from the University of Washington and a BS in Electrical Engineering from University “Politehnica” Bucharest. He works as a Research Scientist for Facebook.
Andrew Sutton: “Generic Programming with Concepts Lite"
In this talk, I will give an overview of the Concepts Lite language extension for C++ and present examples of its use in design and implementation of real-world generic libraries. Concepts Lite provides the ability for programmers to directly state constraints on template arguments as part of the template declaration. These constraints are predicates which determine whether or not a template argument can be used with that template. Constraints are checked by the compiler at the point of use, meaning that that effectively constrained generic libraries will not suffer from the usual problems of insane diagnostics. Libraries written using concepts will be far more readable and maintainable than the status quo. This talk will focus on generic programming, proposed language features, and their use in building real-world libraries. Concepts Lite is a forthcoming ISO Technical Specification (TS) aimed at publication alongside C++14. Concepts Lite is implemented in a branch of GCC, which will be made available to the audience for experiments and experience.
Speaker’s bio: Andrew Sutton is an assistant professor at the University of Akron in Ohio where he teaches and conducts research at the intersection of Software Engineering and Programming Languages. Dr. Sutton helped design and implemented the Concepts Lite proposal for the C++ programming language. He is also the author of the Origin C++ Libraries, an experimental collection of generic libraries that supports ideas and research for generic programming. Dr. Sutton had previously worked as a postdoctoral researcher at Texas A&M University where he worked with Bjarne Stroustrup and Gabriel Dos Reis on the design and implementation of language support for generic programming (i.e., Concepts Lite). He is a member of the C++ Standards Committee and Project Editor for the Concepts Lite Technical Specification. He graduated with a PhD in computer science from Kent State University in Ohio in 2010.
Marshall Clow: “Hardening Your Code"
Ok, you’ve written some code, and it seems to work. How can you be sure that it works? It’s a busy, complicated, dangerous world out there, and software has to work in lots of different environments. How can you gain confidence about your code? How can you make your code more reliable? There are a lot of techniques available to developers today; I’ll talk about several of them: Unit tests, static analysis, runtime analysis, fuzzing, decoding compiler warnings and probably others.
Speaker’s bio: Marshall is a long-time Boost participant. He is one of the moderators of the Boost-Users mailing list, and helps keep the Trac system running. Marshall is a principal engineer at Qualcomm, Inc. in San Diego. He is the author of the Boost.Algorithm library, maintains Boost.Array and Boost.StringAlgo, and is the leader of the Boost Community Maintenance team.
Nate Kohl: “cppreference.com: Documenting C++ One Edit at a Time"
How do you convert hundreds of pages of C++ standardese into a resource that is accessible to software engineers around the world? This talk will describe the process of building a community-run website that documents all of the nooks and dark corners of the C++ programming language. I’ll look back at the history of how C++ was defined, cover the current state of documentation, examine the pros and cons of running a fairly high-profile publicly-editable wiki, and try to guess at what the future holds.
Speaker’s bio: Nate Kohl is a software engineer at Google who enjoys herding cats.
Kate Gregory, James McNellis: “Modernizing Legacy C++ Code"
C++ is a programming language with a long, storied history spanning over three decades–four if one includes its C ancestry. The C++ language has undergone many changes during that time, compiler technology has advanced substantially, and computers today are very different from the computers of decades past. But despite all of these advances, there’s an awful lot of C++ code in use today that looks like it was written in the 1980s. In C++ some cases, the code was written in the 1980s and it’s still in use; in other cases, it’s recently-written code that just doesn’t use modern style. In this talk, we’ll discuss some of the problems with legacy code, and review some practical techniques for applying principles of modern C++ to gradually improve the quality of legacy code and improve maintainability and debuggability. We’ll show how some very small changes to code can yield huge benefits.
Speakers’ bio: Kate Gregory has been using C++ since before Microsoft had a C++ compiler. She writes, mentors, codes, and leads projects, in both C++ and .NET, especially for Windows 7 and 8. Kate is a Microsoft Regional Director, a Visual C++ MVP, and has written over a dozen books (the most recent on C++ AMP for Microsoft Press) and speaks at conferences and user groups around the world. Kate develops courses on C++, Visual Studio, and Windows programming for Pluralsight, founded the East of Toronto .NET Users group, and is a member of adjunct faculty at Trent University in Peterborough.
James McNellis is a senior engineer on the Microsoft Visual C++ team, where he is responsible for the Visual C++ C Runtime (CRT) and C Standard Library implementation. He was previously a member of the Microsoft Expression Blend team, developing the XAML designer tools for Windows 8 apps. Prior to joining Microsoft in 2010, he spent several years working on real-time 3-D simulation and robotics projects in the defense industry. James is a prolific contributor on the Stack Overflow programming Q&A website and occasionally writes for the Visual C++ Team Blog.
By Blog Staff | May 29, 2014 08:38 AM | Tags: None
The countdown continues: Today we are exactly 100 days out from CppCon 2014.
This morning, the organizers announced that CppCon will have some 100 talks, which going by the size of the program likely makes this the biggest C++ event in... ever. Also, we now have the first set of accepted talks.
CppCon Program Preview, 1 of N
by Boris Kolpackov
From the announcement:
Good news: Due to the large number of submissions (we got over 140), the conference will have 6 tracks instead of the planned 5. This means there will be approximately 100 talks, and that’s not counting keynotes, plenary sessions, and lightning talks (more on those soon). As far as we know no other conference has ever had this number of C++-related presentations which will make CppCon 2014 the biggest event in the history of the language.
Understandably, many of you would like to see the conference program before registering. However, due to a greater than expected number of submissions, the final program is still some weeks away. So to help you make up your mind (or convince your boss) we are going to start publishing the talks as they are accepted. So here is the first chunk (summary first, abstracts following):
Scott Meyers: “Type Deduction and Why You Care”
John JT Thomas: “Embarcadero Case Study: Bringing CLANG/LLVM to Windows”
Rachel Cheng, Michael VanLoon: “Boost: A Bridge from C++98 to C++11; An Introduction to Using More Boost”
Titus Winters: “The Philosophy of Google’s C++ Code”
James McNellis: “Unicode in C++”
Scott Meyers: "Type Deduction and Why You Care"
C++98 had template type deduction, and it worked so intuitively, there was little need to understand what took place under the covers. C++11 extends type deduction to include universal references, applies it to auto variables and lambda expressions, then throws in a special auto-only deduction rule. C++14 pushes the boundary further, adding two forms of function return type deduction (auto and decltype(auto)) for arbitrary functions and offering auto parameters for lambdas. The result is that what could be treated as a black box in C++98 has become a topic that practicing C++ developers really need to understand. This talk will give you the information you need to do that.
Speaker’s bio: Scott Meyers is one of the world’s foremost experts on C++ software development. He wrote the best-selling Effective C++ series (Effective C++, More Effective C++, and Effective STL) and is also author of Overview of the New C++ (C++11/14) and Effective C++ in an Embedded Environment.
John JT Thomas: "Embarcadero Case Study: Bringing CLANG/LLVM to Windows"
CLANG/LLVM delivers a highly conforming C++ compiler and architecture for targeting multiple CPUs, and, as such, has seen success in iOS and other operating systems. Embarcadero has successfully delivered the first commercial compiler for Windows based on CLANG/LLVM. This session describes the benefits of CLANG/LLVM as well as the challenges in bringing it to the Windows operating system. Particular emphasis is placed on the managing the changes in CLANG as well as the additional features added to enable Windows development.
Speaker’s bio: John “JT” Thomas, Director of Product Management at Embarcadero Technologies, has more than 15 years of product management and product development experience including hands-on experience with the early versions of Delphi and C++Builder at Borland Software. While at Borland he was a delegate on the ANSI/ISO C++ standards committee. He earned his Computer Science degree from University of California, Santa Cruz and his MBA and MSE from San Jose State University.
Rachel Cheng and Michael VanLoon: "Boost: A Bridge from C++98 to C++11; An Introduction to Using More Boost"
Part one is for those who are stuck with a C++98/03 compiler, but are interested in using more advanced C++11-like strategies. We will discuss some of the differences between C++98 and C++11 while demonstrating how strategic use of Boost libraries can bridge the gap, allowing more modern programming paradigms in many cases. Part two is a deeper dive into some interesting Boost libraries for those who may be new to Boost usage. We will explore how C++98 and C++11 can be enhanced and extended by the additional richness of Boost libraries. We will use as example some of the boost libraries used in the F5 Networks code base. If there is time leftover, we will discuss our experience upgrading GCC.
Speakers’ bio: Rachel Cheng is a recent graduate from The Evergreen State College is currently employed at F5 Networks. Michael VanLoon is a Senior Software Engineer at F5 Networks, is a member of the Northwest C++ Users group, and has attended ISO C++ Standards Committee meetings. He has benefited from time at Microsoft, Yahoo!, and VMware, among others, before joining F5. He is fascinated with crafting code and is dismayed at code that falls short of its potential.
Titus Winters: "The Philosophy of Google’s C++ Code"
The Google C++ Style Guide is a fairly popular guide for C++ coding practices, both at Google and externally, but some of its recommendations often seem dated and have created controversy and perceived tension with more modern C++ In this talk we will focus on the core philosophies underlying that guide, ranging from the common (be consistent) to the unusual (leave an explicit trace for the reader), and debunk the idea that Google’s C++ is anything less than modern. We’ll discuss how these core ideas inform contentious rules like “No non-const references” and “Don’t use exceptions,” and how the application of those rules has worked for us in practice, both as developers and reliability engineers (SREs).
Speaker’s bio: Titus Winters has spent the past three years working on Google’s core C++ libraries. He’s particularly interested in issues of large scale software engineering and codebase maintenance: How do we keep a codebase of over 100M lines of code consistent and flexible for the next decade? Along the way he has helped Google teams pioneer techniques to perform automated code transformations on a massive scale, and helps maintain the Google C++ Style Guide.
James McNellis: "Unicode in C++"
In some programming languages, text processing is easy. Unfortunately, C++ is not one of those languages. C++ lacks good, built-in support for Unicode, though the situation is starting to improve. This session will begin with a brief overview of text encodings, and an introduction to Unicode and the various Unicode encodings. We’ll look at the woeful state of Unicode support in C++98 (or, really, lack thereof), then take a look at the improvements that were made in C++11 and other improvements that have recently been proposed for standardization. We’ll finish up with a discussion of several libraries designed to make it easier to work with Unicode in C++, including the widely-used, open-source International Components for Unicode (ICU) library.
Speaker’s bio: James McNellis is a senior engineer on the Microsoft Visual C++ team, where he is responsible for the Visual C++ C Runtime (CRT) and C Standard Library implementation. He was previously a member of the Microsoft Expression Blend team, developing the XAML designer tools for Windows 8 apps. Prior to joining Microsoft in 2010, he spent several years working on real-time 3-D simulation and robotics projects in the defense industry. James is a prolific contributor on the Stack Overflow programming Q&A website and occasionally writes for the Visual C++ Team Blog.
By Fernando Pelliccioni | May 28, 2014 07:32 PM | Tags: intermediate
[Ed: Note that this article series is not (yet) about C++ code, but it promises to go there and it has an interesting pedigree in its generic programming design analysis (Alex Stepanov) and reviewers (several ISO C++ participants including Andrzej Krzemienski and Dean Michael Berris.]
Writing min function, part 1: The rise of Concepts
by Fernando Pelliccioni
From the article:
This is the first in a series of articles in which I want to transmit what I learned (or what I think I learned) from the books, papers, lectures of Alexander Stepanov.
These are the lessons that Alex gives us, and I want to show them in this series:
- Specify our algorithms correctly
- Programming must be based on a solid mathematical foundation
- Designing our API’s consistently
- Not always the library implementations provided by the programming languages we use are correct, even though they are designed by “experts”.
- The concept of Stability
- Generic programming, of course!
By Blog Staff | May 28, 2014 07:23 PM | Tags: intermediate basics
Today on Kukuruku:
Ref-qualified member functions
by Alexander Kulikov
From the article:
Today I’m going to tell you about a new and a little known (to my mind) C++ feature — reference-qualified member functions. I’ll tell about the rules of such functions overloading and, as an example of use, I’ll show you that with the help of ref-qualified you can try to improve the resource management scheme, which is implemented with the help of another C++ idiom — RAII.
By Blog Staff | May 28, 2014 01:37 PM | Tags: None
A new WG21 paper is available. A copy is linked below, and will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.
Document number: N4051
Date: 2014-05-26
Allow
typenamein a template template parameterby Richard Smith
Excerpt:
Since the introduction of alias templates, C++ has had type templates that are not class templates, and in particular now has template template arguments that are not class templates. However, the syntax for template template parameters still requires the class keyword be used:
template<typename T> struct A {}; template<typename T> using B = int; template<template<typename> class X> struct C; C<A> ca; // ok C<B> cb; // ok, not a class template template<template<typename> typename X> struct D; // error, cannot use typename here... This difference is artificial and is a common surprise. Removing it would make the language simpler.
By Blog Staff | May 28, 2014 01:34 PM | Tags: None
A new WG21 paper is available. A copy is linked below, and will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.
Document number: N4049
Date: 2014-05-27
0-overhead-principle violations in exception handling
by Daniel Gutson, Angel Bustamante, Pablo Oliva, Marcos Diaz
Excerpt:
Sometimes the 0-overhead principle is not honored; one has to pay for things that are not used. An instance where this can be observed is the Exception Handling mechanisms implemented by the diverse toolchains.
In an average computing environment, this has little or no importance; the overhead is minimal and its impact is negligible.
But on embedded systems, where memory is scarce, the overhead imposed by unused language constructs can exceed the capabilities of the available hardware, as we will show is the case for exceptions.
By Blog Staff | May 28, 2014 01:31 PM | Tags: None
A new WG21 paper is available. A copy is linked below, and will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.
Document number: N4046
Date: 2014-05-26
Executors and Asynchronous Operations
by Christopher Kohlhoff
Excerpt:
This proposal builds on the type traits defined in N4045 Library Foundations for Asynchronous Operations. This paper is intended as an alternative proposal to N3785 Executors and schedulers.
The type traits introduced in N4045 Library Foundations for Asynchronous Operations define an extensible asynchronous model that can support:
- Callbacks, where minimal runtime penalty is desirable.
- Futures, and not just
std::futurebut also future classes supplied by other libraries.- Coroutines or resumable functions, without adding new keywords to the language.
The library introduced in this paper applies this asynchronous model, and its design philosophy, to executors. Rather than a design that is restricted to runtime polymorphism, we can allow users to choose the approach that is appropriate to their use case.
Future work will aim to develop guidance on the development of asynchronous operations that participate in an executor-aware model, such as those that integrate operating system services, for example networking support.
By Blog Staff | May 28, 2014 01:29 PM | Tags: None
A new WG21 paper is available. A copy is linked below, and will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.
Document number: N4045
Date: 2014-05-24
Library Foundations for Asynchronous Operations, Revision 2
by Christopher Kohlhoff
Excerpt:
1.1 Changes in this revision
This document supersedes N3964. In this revision, the
handler_type<>trait has been
modified to be SFINAE-friendly, and an extended example has been added to section 9.2 to
illustrate how the traits may be specialised by a user to add a new completion token type.