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Should I Use Overloads or Default Parameters?--Jonathan Boccara

By Adrien Hamelin | Aug 10, 2018 12:01 PM | Tags: intermediate

The answer is not obvious.

Should I Use Overloads or Default Parameters?

by Jonathan Boccara

From the article:

“Should I use overloads or default parameters”, haven’t you asked yourself that question?

When designing an interface where the user can leave the value of an argument up to the API, two approaches are possible:

Using a default parameters:

voiddrawPoint(int x, int y, Color color = Color::Black);
void drawPoint(int x, int y, Color color = Color::Black);

And using overloading:

void drawPoint(int x, int y); // draws a point in black
void drawPoint(int x, int y, Color color);

Which approach is cleaner? Which expresses better the intentions of the interface? Or is it just a matter of style?

This may be subjective, but I’m under the impression that overloading tends to have better popularity than default parameters amongst C++ developers. But I believe that both features have their usages, and it’s usefulto see what makes one or the other more adapted to a given situation.

CppCast Episode 162: The Art of C++ Libraries with Colin Hirsch

By robwirving | Aug 10, 2018 09:14 AM | Tags: None

Episode 162 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Colin Hirsch to discuss his work on The Art of C++ collection of libraries including PEGTL, json and more.

CppCast Episode 162: The Art of C++ Libraries with Colin Hirsch

by Rob Irving and Jason Turner

About the interviewee:

Dr. Colin Hirsch studied Computer Science at the University of Technology in Aachen, Germany in 1993 and later got a PhD in Mathematics from the same university. He worked for two years as a consultant for T-Mobile, developing back-end server applications in C++ and Lua. Later Colin moved to Italy, opened his own business and continued working for T-Mobile (now Deutsche Telekom) as well as working for some other interesting projects like Greenpeace and the Austrian ministry of ecology.

In his free time he enjoys photography, being in nature, science fiction and spending time with his daughter.

CppCon 2017: Practical Techniques for Improving C++ Build Times--Dmitry Panin

By Adrien Hamelin | Aug 8, 2018 12:39 PM | Tags: efficiency

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Practical Techniques for Improving C++ Build Times

by Dmitry Panin

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Slow builds block all C++ developers from the work being done. At Facebook we have a huge codebase, where the time spent compiling C++ sources grows significantly faster than the size of the repository. In this talk we will share our practical experience optimizing build times, in some cases from several hours to just a few minutes. The majority of the techniques are open sourced or generic and can be immediately applied to your codebase.

Facebook strives to squeeze build speed out of everything: starting from a distributed build system, through the compiler toolchain and ending with code itself. We will dive into different strategies of calculating cache keys, potential caching traps and approaches to improve cache efficiency. We tune the compiler, specifically with compilation flags, profile data and link time options. We will talk about the benchmarks we use to track improvements and detect regressions and what challenges we face there. Finally, you will learn about our unsuccessful approaches with an explanation of why they didn't work out for us.

CppCon 2017: Enough x86 Assembly to Be Dangerous--Charles Bailey

By Adrien Hamelin | Aug 6, 2018 01:39 PM | Tags: community

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

Enough x86 Assembly to Be Dangerous

by Charles Bailey

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

This tutorial is an introduction to x86 assembly language aimed at C++ programmers of all levels who are interested in what the compiler does with their source code.

C++ is a programming language that cares about performance. As with any technology, a deep understanding of C++ is helped by knowledge of the layer below, and this means knowledge of assembly language. Knowing what the compiler does with your source code and the limitations under which it operates can inform how you design and write your C++.

We learn how to generate, inspect and interpret the assembly language for your C++ functions and programs. We take a short tour of common assembly instructions and constructs, and discover why extreme caution should be exercised if we are trying to infer performance characteristics from a simple inspection of assembly code.

Starting with a simple `operator+` for a user-defined class, we take a look at how interface and implementation choices affect the generated assembly code and observe the effect of copy elisions and related optimizations that compilers commonly perform.

C++ Foundation Developer Survey "Lite", 2018-08: C++ and Cloud

By Blog Staff | Aug 6, 2018 12:26 AM | Tags: None

cpp_logo.pngThank you to the over 3,000 people who participated six months ago in the Standard C++ Foundation's first-ever global C++ developer survey. Based on its success, we have decided to run these surveys about twice a year to learn about C++ usage generally across industries or in specific current domains.

This time, we focus on the domain of cloud-related software. As the name suggests, it's a one-pager:

C++ Developer Survey "Lite", 2018-08: C++ and Cloud

Please take 10 minutes or so to participate! A summary of the results, including aggregated highlights of common answers in the write-in responses, will be posted publicly here on isocpp.org and shared with the C++ standardization committee to help inform C++ evolution.

The survey will be open for one week.

Thank you for participating and helping to inform our committee and community.

CppCast Episode 161: Expectations and Exceptions with Simon Brand

By robwirving | Aug 3, 2018 08:01 PM | Tags: None

Episode 161 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Simon Brand to discuss his upcoming CppCon talks covering exceptions, value wrappers, debuggers and more.

CppCast Episode 161: Expectations and Exceptions with Simon Brand

by Rob Irving and Jason Turner

About the interviewee:

Simon is a GPGPU toolchain developer at Codeplay Software in Edinburgh. He turns into a metaprogramming fiend every full moon, when he can be found bringing compilers to their knees with template errors and debating undefined behaviour on the C++ Slack channel. He co-organises the Edinburgh C++ user group and contributes to various programming standards bodies.

Outside of programming, he enjoys experimental films, homebrewing, and board games.

CppCon 2017: How to Write Effective Documentation for C++ Libraries...--Robert Ramey

By Adrien Hamelin | Aug 3, 2018 01:18 PM | Tags: community

Have you registered for CppCon 2018 in September? Registration is open now.

While we wait for this year’s event, we’re featuring videos of some of the 100+ talks from CppCon 2017 for you to enjoy. Here is today’s feature:

How to Write Effective Documentation for C++ Libraries...

by Robert Ramey

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

With the success of GitHub, everybody and his brother is a library developer. Programmers love to create code, upload it to GitHub and hope for immortality. Most projects get only the most cursory examination before being passed over by users. Why is that? GitHub considered the problem.

GitHub just published its 2017 Open Source Survey. The popular social coding service surveyed over 5,500 members of its community, from over 3,800 projects on github.com. It also spoke to 500 coders working on projects from outside the GitHub ecosystem. The Open Source Survey asked a broad array of questions. One that caught my eye was about problems people encounter when working with, or contributing to, open source projects. An incredible 93 percent of people reported being frustrated with “incomplete or confusing documentation”. see https://thenextweb.com/dd/2017/06/02/...

Even the most experienced and dedicated software developers can't do it. This can be confirmed by looking over recent reviews of Boost libraries. The most common complaint is that the documentation isn't useable.

Programmers love their stuff and hope to get people to use it, why don't they fix their documentation? The reason is simple: They don't know how.

Problems

a) It's tedious and boring to write
b) Developers don't know what to include and what to exclude
c) Tools make things harder
d) Regardless of the amount of effort invested, the end result is usually of little or no value.

This presentation will present a "Cookbook" and demonstration for creating documentation. Using this method will

a) Much diminish the tedium of the task.
b) Help improve to the quality of library design and implementation
c) Create something that is useful to the library user.

We will touch upon tools like Doxygen, etc. But this is only a small portion of the presentation. We use them so they deserve mention. But they don't cause the problem, and they don't solve it either.