C++ is an old language. Many aspects of our programming styles have become habits that we do not think about too much today. In this blog, I’m going to address one major issue that has resulted from such habits and get you prepared for a new bright world of C++2b. So without further ado, let’s […]
Blog Archives
Shader Variants Explosions of the Combinatorial Kind
Pimpl for Small Classes
The familiar solution for thick value classes that want to preserve binary compatibility is to use the pimpl pattern (private implementation), also known as d-pointer (pointer to data). In future versions of our class, we can freely change the contents of the pimpl (i.e. adding, removing, and/or modifying data members) but the binary compatibility of […]
FMA Woes
Floating-point math is hard, and compilers will exploit every language loophole to make our FP calculations go faster, sometimes with surprising results.
QObjects, Ownership, propagate_const and C++ Evolution Const Correctness in Qt Applications
A very common implementation pattern for QObject subclasses is to declare its child QObjects as data members of type “pointer to child.” Raise your hand No, keep your hand on your computer input device 🙂 Nod if you have ever seen code like this (and maybe even written code like this yourself): A fairly common […]
On QVarLengthArray and Uninitialized Storage in C++
If you’re following our Youtube channel you might have heard me talking about QVarLengthArray. If you’re not… you should follow us! But let me give you a quick recap. QVarLengthArray is a Qt container that acts like a vector; its elements are stored contiguously in memory and it has a dynamic size. At any time […]
C/C++ Profiling Tools
This blog will give you a brief overview of profiling C and C++ applications. Additionally, it will lay before you all of the tools available, with the purpose of aiding you in choosing the right tools at the right times.
CXX-Qt 0.4 Released
We just released CXX-Qt version 0.4! CXX-Qt is a set of Rust crates for creating bidirectional Rust ⇄ C++ bindings with Qt. It can be used to integrate Rust into C++ applications using CMake or build Rust applications with Cargo. CXX-Qt provides tools for implementing QObject subclasses in Rust that can be used from C++, […]
Understanding qAsConst and std::as_const
Every now and then, when I submit some code for a code review, people tell me that I forgot qAsConst. Now I have one more enemy, namely: Clazy! It has also started saying this, and I guess it’s about time for me to figure out what is going on. When do I need qAsConst and […]
Structured Bindings with Qt SQL
Some time ago, I wrote a post about integrating Qt’s associative containers with the fancy new C++ features, range-based for loops with structured bindings. That post inspired KDAB’s own Giuseppe D’Angelo to add the asKeyValueRange member function to both QHash and QMap. Now it’s possible to iterate over them with a simple range-based for loop, […]