October 25, Pavia, Italy
November 6-8, Berlin, Germany
November 3-8, Kona, HI, USA
By Marco Arena | Jan 18, 2024 01:20 AM | Tags: sobjectizer intermediate c++20
A new episode of the series about SObjectizer and message passing:
SObjectizer Tales – 15. Monitoring disconnections
by Marco Arena
From the article:
In this episode we incorporate an automatic mechanism to detect client disconnections.
By Blog Staff | Jan 16, 2024 04:20 PM | Tags: None
Writing efficient code is challenging but worthwhile. Andrew Drakeford demonstrates how SIMD (Single Instruction Multiple Data) can reduce your carbon footprint.
Use SIMD: Save The Planet
by Andrew Drakeford
From the article:
Some sources claim that data centres consumed 2.9% of the world’s electricity in 2021 [Andrae15]. With the recent sharp increase in energy prices, many firms became aware of this cost. Additionally, trends in AI use and the near-exponential growth in both network and data services projected over the next few years [Jones18] suggest that this situation will only get worse.
A data centre’s single purpose is to run our software (not heat the planet). But what if the processing cores that our software runs on have a unique, often unused, feature that would enable them to do the work several times faster? Would this also mean several times more efficiently? This feature is SIMD (Single Instruction Multiple Data).
SIMD is a parallel computing technology that allows processors to perform the same operation on multiple data elements simultaneously. By using SIMD instructions, a single CPU instruction can operate on multiple data elements in a single clock cycle. For example, with 256-bit SIMD registers, it is possible to process eight 32-bit floating-point numbers or sixteen 16-bit integers in parallel. This leverages the data-level parallelism inherent in many algorithms, such as mathematical computations, image processing, audio processing, and simulations. Figure 1 illustrates the element-wise addition of two sets of numbers using the SSE2, AVX2 and AVX512 instructions sets.
SIMD instructions use vector registers, which can hold multiple data elements. These registers allow the CPU to apply a single instruction to all the elements simultaneously, thus reducing the instruction count. Consequently, SIMD can provide a substantial speedup for tasks that exhibit regular and parallelizable data processing patterns.
By Marco Arena | Jan 11, 2024 12:52 AM | Tags: sobjectizer intermediate c++20
A new episode of the series about SObjectizer and message passing:
SObjectizer Tales – 14. Triggering agent shutdown
by Marco Arena
From the article:
In this episode we delve into the process of deregistering an active agent, along with all its related resources and subscriptions.
By Blog Staff | Jan 10, 2024 09:20 AM | Tags: None
In this article, we’ll explore six practical string processing operations introduced in C++20 and C++23. These features represent an evolution in this crucial area, covering a spectrum of operations from searching and appending to creation and stream handling.
Six Handy Operations for String Processing in C++20/23
by Bartlomiej Filipek
From the article:
Let’s start with a simple yet long-awaited feature…
1.
contains(), C++23Finally, after decades of standardization, we have a super easy way to check if there’s one string inside the other. No need to use
.find(str) != npos!Before C++23:
And now, thanks to the proposal: P1679R3:
As you can see, the new approach with contains() is more straightforward and intuitive.
By Giovanni Dicanio | Jan 9, 2024 11:33 AM | Tags: None
Have you ever wondered how to correctly print Unicode text to the Windows console in your C++ programs? Maybe you tried something, and you got meaningless output, or even an assertion failure at runtime, pointing to some obscure code in the CRT? Well, then this article is for you!
How to Print Unicode Text to the Windows Console in C++
by Giovanni Dicanio
From the blog post:
Suppose that you want to print out some Unicode text to the Windows console. From a simple C++ console application created in Visual Studio, you may try this line of code inside main:
std::wcout << L"Japan written in Japanese: x65e5x672c (Nihon)n";As you can see, the Japanese kanjis are not printed. Moreover, even the “standard ASCII” characters following those (i.e.: “(Nihon)”) are missing. There’s clearly a bug in the above code.
How can you fix that?
Well, the missing piece is ...
By John Farrier | Jan 9, 2024 10:54 AM | Tags: c++20
Learn about C++20's Callable Concepts, how they improve on SFINAE, and how to use them in your own code.
Breaking Down C++20 Callable Concepts
By John Farrier
From the article:
C++20 Callable Concepts refer to a powerful feature introduced in the C++20 standard that allows developers to specify and enforce constraints on function objects, lambdas, and other callable entities in a more expressive and type-safe manner. Callable Concepts enable the compiler to check if a given callable meets specific requirements, such as having certain member functions or satisfying particular type traits, before allowing it to be used in a template or function. This helps improve code readability, maintainability, and error detection, as it provides clearer and more structured ways to define the expected behavior and capabilities of callables in C++ code.
By Giovanni Dicanio | Jan 9, 2024 10:53 AM | Tags: None
Integer overflows can be hidden inside your C++ code and can cause subtle nasty bugs.
Fortunately, it's easy to guard your code against those subtle bugs, thanks to an open-source easy-to-use library:
Protecting Your C++ Code Against Integer Overflow Made Easy by SafeInt
by Giovanni Dicanio
From the article:
In previous blog posts I discussed the problem of integer overflow and some subtle bugs that can be caused by that. (...)
Of course, writing this kind of complicated check code each time there is a sum operation that could potentially overflow would be excruciatingly cumbersome, and bug prone! (...)
Fortunately, you don’t have to do all that work! In fact, there is an open source library that does exactly that! This library is called SafeInt. (...)
The code will still look nice and simple, but safety checks will happen automatically under the hood. Thank you very much SafeInt and C++ operator overloading!
By Marco Arena | Jan 4, 2024 01:40 AM | Tags: sobjectizer intermediate c++20
A new episode of the series about SObjectizer and message passing:
SObjectizer Tales – 13. Routing images across the network
by Marco Arena
From the article:
In this episode we add a new functionality to the service that allows clients to receive images in streaming.
By Blog Staff | Jan 2, 2024 04:46 AM | Tags: None
In my previous post, "Why you shouldn't provide an empty destructor," we discussed the importance of not providing an empty destructor in most cases. However, in this post, we'll explore a rare exception to this rule that arises when using the PImpl idiom to hide implementation details, specifically in situations where the unique_ptr encounters issues with incomplete types. Let's delve into this exception and learn when it's necessary to provide an empty destructor.
When an Empty Destructor is Required
by Andreas Fertig
From the article:
As you probably know from life, not only programming. There is no rule without an exception. Let's talk about the one case that requires an empty destructor (yes, I know it sounds silly). Suppose you have the following code:
In file included from <source>:2: In file included from /opt/compiler-explorer/gcc-12.2.0/lib/gcc/x86_64-linux-gnu/12.2.0/../../../../include/c++/12.2.0/memory:76: /opt/compiler-explorer/gcc-12.2.0/lib/gcc/x86_64-linux-gnu/12.2.0/../../../../include/c++/12.2.0/bits/unique_ptr.h:93:16: error: invalid application of 'sizeof' to an incomplete type 'Orange' static_assert(sizeof(_Tp)>0, ^~~~~~~~~~~ /opt/compiler-explorer/gcc-12.2.0/lib/gcc/x86_64-linux-gnu/12.2.0/../../../../include/c++/12.2.0/bits/unique_ptr.h:396:4: note: in instantiation of member function 'std::default_delete<Orange>::operator()' requested here get_deleter()(std::move(__ptr)); ^ <source>:4:7: note: in instantiation of member function 'std::unique_ptr<Orange>::~unique_ptr' requested here class Apple ^ <source>:6:27: note: forward declaration of 'Orange' std::unique_ptr<class Orange> mOrange{}; ^ 1 error generated. Compiler returned: 1
Essentially, this message tells you that thestd::unique_ptrcannot instantiate the required destructor for itself typed withOrange. The simple reason is that, at this point,Orangehas no visible destructor. Which is the entire point of the PImpl idiom. What now?
By Blog Staff | Dec 28, 2023 01:26 PM | Tags: None
Release 1.84.0 of the Boost C++ Libraries is now available.
These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use.
Release 1.84.0 contains two new libraries and numerous enhancements and bug fixes for existing libraries.
New Libraries
Here are some useful links for 1.84.0.
Marshall Clow and Glen Fernandes managed this release - we very much appreciate their continued hard work!
