Specifically Tauri uses web views that are based on Chrome or Safari on systems, and only if they don't exist by default will it package it, which somehow still ends up smaller than electron. But on Mac and Windows it is tiny, and on Linux it is still surprisingly much smaller than electron, but it is a consistent environment.
When initializing a GPU context you can specify whether you want the most efficient device, the fastest device, etc, for a GUI app then you would want to pick the most efficient, which is a single flag to pass in, or supply options and let the user pick which one they want.
Rust actually has a library with very good flutter integration, it does require using dart for the actual flutter part though, but it works well together.
Rust may give a subset of file system functionality that all general file systems should in theory support in the front interface, but you can access platform specific functionality by asking for the extended interface, which you put inside a platform check block. You have the full functionality there.
So very much so. All the usual C types are available, you even have as much control as even saying that you want to struct laid out as it is in C, doing something as simple as binding a function is just declaring the function like you would in C. As it uses llvm it can even inline across C code, optimize and all just like they were written in the same language if you wish to do that.
Honestly curious, but of all the things I've heard people say about QT it could never be about poor performance, it's generally consistently regarded as the fastest complete GUI toolkit out. Even more so because the Linux desktop environment KDE is built in it and is consistently shown to be both the fastest and lowest memory of near all Linux desktop environments (and certainly among all the big ones), including ones designed to be fast and low memory. Where did this poor performance thing come from and am I missing something lately?
This is the first time I hear this compliment about KDE: being high performance and low memory usage. It's the exact opposite in my experience. The worst performance and most resource hungry desktop environment.
Though to be honest it's been more than 5 years since I tried, so things might have changed since then ... but I really doubt it.
More likely, I would wager that they were just overwriting the instructions to draw with new instructions that just inline everything so it didn't need to fetch out to anything.