In the last post of this series we learned that: erasing elements from the middle of a vector can be implemented, in general, via a series of move assignments, move constructions, swaps, destructions for types with value semantics, the exact strategy does not really matter for types with write-through reference semantics, the strategy matters, because […]
Blog Archives
Qt and Trivial Relocation (Part 3) Trivial relocability for vector erasure, and types with write-through reference semantics
In the last post of this series we started exploring how to erase an element from the middle of a vector. We discussed that in principle there are several different possible ways to implement erase().For instance, a vector could move-assign over the elements to be erased:Alternatively, a vector could use rotations or some other algorithms […]
Qt and Trivial Relocation (Part 2) Relocation and Erasure
In the last post of this series we discussed the usage of trivial relocation in order to optimize move construction followed by the destruction of the source. To quickly recap: objects of certain datatypes (“trivially relocatable” types) can be moved in memory by simply moving bytes; this can be used to optimize certain bulk operations […]
Qt and Trivial Relocation (Part 1) What is relocation?
The container classes introduced in Qt 4 (Tulip, for the aficionados) had an interesting optimization: the ability to turn certain operations on the contained objects into byte-level manipulations. Example: vector reallocation Consider the reallocation of a QVector<T>: when the vector is full and we want to insert a new value (of type T), the vector […]
Hotspot v1.5.0 released The Linux perf GUI for Performance Analysis
Hotspot is a standalone GUI designed to provide a user-friendly interface for analyzing performance data. It takes a perf.data file, parses and evaluates its contents, and presents the results in a visually appealing and easily understandable manner. Our goal with Hotspot is to offer a modern alternative to perf report, making performance analysis on Linux […]
Qt 6 WASM: Uploading & Playing Back Audio Files Adapting to the limitations of the web platform and Qt Multimedia
This article walks through an implementation using C++11 or later, Qt 6.5 or later for WebAssembly (multithreaded), and CMake. The browser environment used was Mozilla Firefox 119.0.1 (64-bit) provided by the Mozilla Firefox snap package for Ubuntu. Overview & Motivation Lately, I’ve been working on a small Qt Widgets project to help manage some weekly […]
CXX-Qt 0.6 Release
We just released CXX-Qt version 0.6! 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++, […]
Supercharging VS Code with C++ Extensions
In a previous blog we demonstrated the most straightforward method to optimize Visual Studio Code for a Qt / C++ environment: simply let the tools do all the work! The example GitHub project we discussed automatically installs both the Microsoft C/C++ and clangd extensions into VS Code. You might wonder why you need both C++ […]
Qt for VS Code, the TL;DR version Using VS Code IDE to work on Qt project
Our colleague Alessandro Ambrosano created a series of blogs (parts 1, 2, and 3) that explain how to get Visual Studio Code configured for Qt development. In that series, Alessandro covers all the details you need to get your VS Code environment configured exactly the way you want it. But there’s a lot there to […]
PSA: QPointer has a terrible name
Today’s blog post is about a small utility class in Qt with a… questionable name: QPointer. If you’re new to Qt, maybe don’t check out QPointer’s documentation just yet, and try to guess what the class does based on its name alone. I’ve seen countless users being very confused by it. Some end up using […]