See My Talk: Empty Base Class Optimisation, [[no_unique_address]] and other...--Bartlomiej Filipek

By Adrien Hamelin | Aug 3, 2020 11:25 AM | Tags: community c++20

Will you use it?

See My Talk: Empty Base Class Optimisation, [[no_unique_address]] and other C++20 Attributes

by Bartlomiej Filipek

Summary of the talk:

Sometime in 2016, I wrote an article about custom deleters for smart pointers.

Bartek’s coding blog: Custom Deleters for C++ Smart Pointers

And there is an interesting property that if you have a unique_ptr and you provide a stateless functor, then the size of unique_ptr is just one pointer (not two when you use a function pointer). But at that time, I didn’t investigate what the exact reason behind this capability was.

Then in February 2020, I gave a presentation on our C++ User Group about all of the C++20 features. And among them, there’s a new attribute called [[no_unique_address]]. At that time, I also had no clear idea of what were the use cases for it.

But then I wanted to understand more of C++20 and somehow those two features: deleters for unique_ptr and [[no_unique_address]] started to “converge”.

As it appears with the new attribute from C++20, we can significantly simplify the code that leverages Empty Base Class Optimisation to create things like “compressed pairs” often used to store stateless callable objects like allocators or deleters.

Thirty Years C++. Interview with Bjarne Stroustrup--Roberto V. Zicari

By Adrien Hamelin | Aug 3, 2020 11:23 AM | Tags: community

An interesting read.

Thirty Years C++. Interview with Bjarne Stroustrup

by Roberto V. Zicari

From the article:

“If you keep your good ideas to yourself, they are useless; you could just as well have been doing crossword puzzles. Only by articulating your ideas and making them accessible through writing and talks do they become a contribution.” –Bjarne Stroustrup

Back in 2007 I had the pleasure to interview Bjarne Stroustrup, the inventor of  C++ programming language. Thirteen years later…, I still have the pleasure to publish an interview with Bjarne...

Reminder: CppCon 2020 early bird registration ends in two days

By Blog Staff | Aug 3, 2020 10:19 AM | Tags: None

Just a reminder, early bird registration for the all-virtual CppCon 2020 ends in two days. Register soon to get the reduced rate for you and your team members! After August 5th, registrations will still be available at the regular rate.

CppCon 2020 will be held as an online conference. Registered attendees will get the full experience:

• Talks delivered live, with live Q&A opportunities with speakers during their talks and in the "hallway track."
• Virtual exhibitor booths, where you can interact live via videoconference with your favorite C++ product's developers.
• The "hallway track," live video chat with other attendees at virtual tables with whiteboards.
• ... and much more, including lightning talks, additional pre/post-conference classes, and the CppCon house band performing live from their studio in Seattle.

As always, the talk videos will be made freely available to everyone online about a month or two after the event. The other parts of the conference are not recorded, but are available live.

CppCon 2019: Naming is Hard: Let's Do Better--Kate Gregory

By Adrien Hamelin | Jul 31, 2020 08:00 PM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Naming is Hard: Let's Do Better

by Kate Gregory

Summary of the talk:

C++ developers are famously bad at naming: our idioms, guidelines, and lore are rich in examples of terrible names. For example, consider RAII, which stands for scope bound resource management, or west const which perhaps should be const west, or all the samples that feature an object called x which is an instance of a class called X, and so on.

The good news is that naming well is a learned skill, and you can learn it, and start to name better right away. In this talk, I'll tell you why names matter, what benefits a good name can bring, and how to be better at naming. I'll discuss some categories of names and some common decisions within those categories. I'm not going to give you a set of rules to follow: this is about thinking and considering the meaning of the things you are naming. I will give you some questions to ask yourself and some structure that I use to help me to help those who read what I write.

I'll also address renaming things in existing (legacy) code, why and when to do it, and why getting it right the first time may not even be a realistic goal. You should be a lot more confident naming things after we spend this time together.

CLion 2020.2 release: Makefile projects, C++20, enhanced static analysis, and doctest support

By Anastasia Kazakova | Jul 30, 2020 12:26 PM | Tags: None

CLion 2020.2 is released!

CLion 2020.2: Makefile Projects, C++20, Enhanced Code analysis, Doctest, and Other Unit Testing Support Improvements

by Anastasia Kazakova

From the article:

CLion 2020.2 covers a wider variety of C and C++ projects and makes modern C++ coding easier. Here are the highlights:

• Project models
  • Initial support for Makefile projects
  • CMake upgrade to 3.17
• C++20 standard compliance
  • Code completion for C++20 keywords
  • Code completion in designated initializers
  • Support for the explicit(bool) construct in name hints, navigation, and refactorings
  • Range-based for loops with the init statement are now supported
• Code analysis
  • A new inspection to constrain a function's result
  • Dangling pointer check
  • A more accurate Simplify inspection
  • Check for a loop condition that is never updated
  • New Inspection Widget and new Problems View
• Support for Doctest, and improved integration with Catch2 and Google Test 1.10
• Automatic creation of code coverage profiles
• PlatformIO plugin enhancements
• VCS:
  • Git installed in WSL2
  • A more helpful GitHub Pull Requests View
• Performance improvements

std::ref and std::reference_wrapper: Common use cases -- Hitesh Kumar

By Hitesh Kumar | Jul 30, 2020 12:24 PM | Tags: None

Motivation behind reference_wrapper and common use cases.

std::ref and std::reference_wrapper: Common use cases

by Hitesh Kumar

From this article:

An std::reference_wrapper is a copyable and assignable object that emulates a reference. Contrary to its name, it does not wrap a reference. It works by encapsulating a pointer (T*) and by implicitly converting to a reference (T&). It cannot be default constructed or initialized with a temporary; therefore, it cannot be null or invalid.

CppCon 2019: There Are No Zero-cost Abstractions--Chandler Carruth

By Adrien Hamelin | Jul 29, 2020 08:00 PM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

There Are No Zero-cost Abstractions

by Chandler Carruth

Summary of the talk:

C++ is often described as providing zero-cost abstractions. Libraries offer up facilities documented as such. And of course, users read all of these advertisements and believe that the abstractions they are using are truly zero-cost.

Sadly, there is no truth in advertising here, and there are no zero-cost abstractions.

This talk will dive into what we mean by "zero-cost abstractions", and explain why it is at best misleading and at worst completely wrong to describe libraries this way. It will show case studies of where this has led to significant problems in practice as libraries are designed or used in unscalable and unsustainable ways. Finally, it will suggest a different framing and approach for discussing abstraction costs in modern C++ software.

CppCon 2019: Converting to C++20 Modules-Nathan Sidwell

By Adrien Hamelin | Jul 27, 2020 08:00 PM | Tags: community

This year, CppCon 2020 is going virtual. The dates are still the same – September 14-18 – and we are aiming for the CppCon live event to have pretty much everything you’re familiar with at CppCon except moved online: multiple tracks including “back to basics” and a new “embedded” track; live speaker Q&A; live talk time zones friendly to Americas and EMEA (and we’re going to try to arrange around-the-clock recorded repeats in all time zones, where speakers who are available can be available for live Q&A in their repeated talks too, and we’ll do that if it’s possible – but we’re still working on it!); virtual tables where you can interact face-to-face online with other attendees just like at the physical event; virtual exhibitor spaces where you can meet the folks on your favorite product’s teams to ask them question face-to-face; pre- and post-conference classes; and even the CppCon house band playing live before every plenary session. All talk recordings will be freely available as usual on YouTube a month or two after the event, but everything else above will be available only live during CppCon week.

To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2020 – all the spirit and flavor of CppCon, this year all virtual and online!

Converting to C++20 Modules

by Nathan Sidwell

Summary of the talk:

C++20 will have a module system, which provides benefits beyond simple code hygiene. C++20 modules uses new keywords and explicit source-level annotations. How do we get there from here?

I have been implementing this in the GNU compiler, and will talk about the broad strokes of the module specification.
I will describe how:
* one may incrementally convert source code,
* build systems might be augmented,

2020-07 mailing available

By Administrator | Jul 27, 2020 10:31 AM | Tags: None

The 2020-07 mailing of new standards papers is now available.

DeepEnds 3.5: Make public members private

By zebedee | Jul 27, 2020 09:28 AM | Tags: None

CycleRouter Ltd has released version 3.5 of their DeepEnds dependency analysis tool. A highlight:

Report and/or automatically rewrite public members that should be private

From the release announcement:

DeepEnds includes other dependency analysis tools to analyse coupling and cohesion, delete redundant code and

identify classes to extracted from C code. It parses C++, C# and Visual Basic source code.

The software is free to use until the end of August and will now install successfully via NuGet.