Prepping Yourself to Conceptify Algorithms -- Christopher Di Bella

By Christopher Di Bella | May 16, 2018 12:24 PM | Tags: c++20

In this article, we explore what concepts are, where they are useful, and how they are different to things that exist in vanilla C++17.

Prepping Yourself to Conceptify Algorithms

by Christopher Di Bella

From the article:

A very quick summary of this document is that constraints are requirements imposed on syntax, axioms are requirements imposed on semantics, and concepts are both constraints and axioms together.

...

Let’s build the EqualityComparableWith concept from the Ranges TS, from the ground up.

C++ Weekly Episode 115: Compile Time ARM Emulator—Jason Turner

By Jason Turner | May 14, 2018 02:47 PM | Tags: intermediate efficiency c++17

Episode 115 of C++ Weekly.

Compile Time ARM Emulator

by Jason Turner

About the show:

This episode of C++ Weekly demonstrates a compile time ARM CPU emulator using C++17 constexpr. No special tricks were necessary to accomplish this feat, merely following a rule of "constexpr everything that is reasonable." The code is portable and currently compiles with GCC and Clang in about 2 seconds for simple compile-time test cases.

Using C++17 std::optional -- Bartlomiej Filipek

By bfilipek | May 14, 2018 08:55 AM | Tags: c++17

See how and when std::optional from C++17 is useful:<img alt="" data-cke-saved-src="https://dl.dropboxusercontent.com/s/nv9s71vz8kq8pq3/stdoptusing.png?dl=0" src="https://dl.dropboxusercontent.com/s/nv9s71vz8kq8pq3/stdoptusing.png?dl=0" 400px;="" height:="" 128px;="" float:="" right;"="" style="height: 74px; width: 230px; float: right;">

Using C++17 std::optional

by Bartlomiej Filipek

From the article:

By adding the boolean flag to other types, you can achieve a thing called “nullable types”. As mentioned, the flag is used to indicate whether the value is available or not. Such wrapper represents an object that might be empty in an expressive way (so not via comments )

2018-05 pre-Rapperswil mailing available

By Blog Staff | May 12, 2018 06:32 AM | Tags: None

The full 2018-05 mailing of new standards papers is now available.

CppCast Episode 149: CppChat with Phil Nash

By robwirving | May 11, 2018 07:24 PM | Tags: None

Episode 149 of CppCast the only podcast for C++ developers by C++ developers. In this episode Rob and Jason are joined by Phil Nash to discuss the rebooted CppChat show, test driven development, a conference announcement and much more.

CppCast Episode 149: CppChat with Phil Nash

by Rob Irving and Jason Turner

About the interviewee:

Phil has spent the last year and a half doing things that might sound interesting for the next time he’s interviewed on CppCast. He might have overdone it. Aside from that he’s most commonly known as the original author of the test framework, Catch2. He’s been in or around C++ since the early 90s, but started coding in 1981 on a ZX-81 that he borrowed for six months. He’s worked in many domains, including finance and mobile and is now developer advocate for C++ and Swift tools at JetBrains.

Non-Ownership and Generic Programming and Regular types, oh my!==Barry Revzin

By Adrien Hamelin | May 11, 2018 12:41 PM | Tags: intermediate

Do you know about it?

Non-Ownership and Generic Programming and Regular types, oh my!

by Barry Revzin

From the article:

This post is about a specific collection of types in the C++ core language and standard library. I am not sure of a good way to name this collection, and some terms that come to mind come with their own baggage, so I’m going to for now group them together under an umbrella that is clearly widely unrelated to programming and call them Westie types (because, like my dog, they are awesome yet enigmatic).

Modern C++ Features – std::variant and std::visit--Arne Mertz

By Adrien Hamelin | May 11, 2018 12:29 PM | Tags: stl intermediate

Do you use them?

Modern C++ Features – std::variant and std::visit

by Arne Mertz

From the article:

std::variant is a library addition in C++17 for sum types, and std::visit is one of the ways to process the values in a std::variant.

IO2D demo: CPULoad -- Michael Kazakov

By Blog Staff | May 10, 2018 12:35 PM | Tags: None

A walkthrough of the CPULoad demo from the 2D Graphics proposal:

IO2D demo: CPULoad

by Michael Kazakov

From the article:

In my humble opinion, the 2D graphics proposal might bring C++ a solid foundation for visualization support. It’s powerful enough to build complex structures on top of it – here I can refer to the sample SVG renderer as an example. At the same time, it’s not built around some particular low-level graphics API (i.e OpenGL/DirectX/Mantle/Metal/Vulkan), which come and go over time (who remembers Glide?). What is also very important about the proposal is its implementability – I wrote the CoreGraphics backend in ~3 months on a part-time basis. It can be assumed that writing a theoretical Direct2D backend might take about the same time. While it’s easy to propose “just” a support for PostScript, SVG or even HMTL5, the practical implementability of such extensive standards is very doubtful. Having said that, I do think that the proposal, while being a valid direction, is far from being perfect and needs a lot of polishing.

Quick Q: Undefined behavior and sequence points

By Adrien Hamelin | May 10, 2018 11:48 AM | Tags: advanced

Quick A: No quick A.

Recently on SO:

Undefined behavior and sequence points

What are "sequence points"?

What is the relation between undefined behaviour and sequence points?

I often use funny and convoluted expressions like a[++i] = i;, to make myself feel better. Why should I stop using them?

If you've read this, be sure to visit the follow-up question Undefined behavior and sequence points reloaded.

(Note: This is meant to be an entry to Stack Overflow's C++ FAQ. If you want to critique the idea of providing an FAQ in this form, then the posting on meta that started all this would be the place to do that. Answers to that question are monitored in the C++ chatroom, where the FAQ idea started out in the first place, so your answer is very likely to get read by those who came up with the idea.)

Quick Update on C++ Compiler Bug Hunt--No Bugs" Hare

By Adrien Hamelin | May 10, 2018 11:43 AM | Tags: community

Looking for the bug.

Quick Update on C++ Compiler Bug Hunt

by No Bugs" Hare

From the article:

Some time ago, I wrote a post about kscope – mini-project on finding and reporting bugs in modern C++ compilers. The point was that there is a way to use C++ facilities to make C++ code self-mutating (more strictly – pseudo-randomized using externally supplied ITHARE_KSCOPE_SEED macro), which allows finding certain classes of bugs during randomized testing. In the previous post, I wrote about 12 bugs reported, with 3 of them already fixed. I have to admit that since that point, I didn’t have as much time as I’d like to spend on kscope; still, 3 more bugs were reported (2 of them being codegen bugs) – and quite a few were fixed (fortunately, bugfixing is one thing which doesn’t require my participation <wink />)...