> Something that isn't talked about much in the GUI world (outside of mobile development) is how essential multi-threading is to a great application experience.
Yes it is. Heavyweight desktop GUI applications like DAWs or CAD or image/video editing are old established technology.
> This has the advantage of a project feeling natural to the platform while still allowing for code reuse between platforms
Having written cross platform native applications: This is a pain in the ass to do well - and there isn’t a particular reason this hasn’t been doable in C/C++ since forever - Rust isn’t some silver bullet. “Abstracting” away the native GUI/UX seems to be a common pitfall for junior devs - how hard can it be they think - then they learn why Qt exists.
> It's not too far from the write-once-run-everywhere philosophy of React native, Electron and similar.
Electron is about as far removed from the philosophy of targeting platform native toolkits as one can get.
> Rust isn't some silver bullet
Rust codebases extend in size and scale to larger teams fundamentally better than C++ / C. Rust offers more leverage in building ambitious system software.
Since you mention Qt, imagine writing all of Qt in x86 assembly, vs. C++. "There's not particular reason this isn't doable." C++ to Rust is a similar jump. No silver bullets; just leverage.
Cross-platform toolkits — especially those aiming to abstract over native UI/UX patterns — are an ambitious, if not Sisyphean domain. Qt was about the best we could do in the C++ era, but a new era has dawned.
> Qt was about the best we could do in the C++ era, but a new era has dawned.
Based on the way the Rust community has been spinning its wheels for years in getting something even within a light year of feature parity with Qt, if a new era has truly dawned you might need to wait for the next one.
> Rust codebases extend in size and scale to larger teams fundamentally better than C++ / C. Rust offers more leverage in building ambitious system software.
I like Rust - but this is classic RSF/RIIR copypasta.
> getting something even within a light year of feature parity with Qt.
Qt is also old as Jesus, and making a cross OS GUI is extremely hard.
And you can non-ironically say the same about non-Qt toolkit written in C++.
What grandparent probably means something that leverages parallelism and/or GPU acceleration.
> And you can non-ironically say the same about non-Qt toolkit written in C++.
Maybe. Gtk and its related libraries don’t cover everything Qt does, but they’re not small either. It’s also fair to include the native toolkits themselves on their respective platforms that are written in a mixture of C++/C/Objective C.
I also will point out that one of the cross platform toolkits with some traction in the Rust world is amusingly fltk.
> What grandparent probably means something that leverages parallelism and/or GPU acceleration.
You mean like QtQuick/QML, skia (basically this is the effective underpinning of electron and flutter) or Dear Imgui, etc. There are a handful of widely used GPU based GUI libraries. The above examples are all C++.
> leverages parallelism
The memory model of Rust is still whatever C++ does. I get that Rust has some nice features and C++ makes it easy to fuck your self but people have been doing large scale parallel software development for years in C++.
> Qt is also old as Jesus, and making a cross OS GUI is extremely hard.
The claim was we are in a new era of “leverage” that will make the hard very easy (that’s what it sounded like at least). I found the claim at best vague and low on specifics or evidence - hence the mention of RESF.
And therein lies the problem. Qt is semi-open (the parent company tried to close source it[1]). If a commercial company has no interest in maintaining it, there is even less hope for other open source approaches.
Best cross OS system are almost always backed by a commercial supporter. See Skia - Google, Java Swing - Oracle, Qt - QtCompany, etc.
OSS offerings were always runner ups (e.g. Gtk - Gnome).
> The memory model of Rust is still whatever C++ does. I get that Rust has some nice features and C++ makes it easy to fuck your self but people have been doing large scale parallel software development for years in C++.
Memory model of Rust is undefined[2]. It might be anything Rust does to accomodate C++ bindings, but I don't think they really settled on one.
I'd like to add - people have been doing large scale parallel software development for years in C++, in spite of C++. What is a line of comment in C++ in Rust is a type system constraint.
It's a difference between having a seatbelt (Rust) and holding a piece of seatbelt (C++).
Rust was literally made to address C++ shortcomings when it comes to parallelism.
> You mean like QtQuick/QML, skia (basically this is the effective underpinning of electron and flutter) or Dear Imgui, etc. There are a handful of widely used GPU based GUI libraries. The above examples are all C++.
No. I mean like WebRenderer[3], Lyon[4]. Most things should be parallelized and done on GPU/SIMD. Layout, font shaping, etc.
[1]https://news.ycombinator.com/item?id=25656932
[2]https://doc.rust-lang.org/reference/memory-model.html