"I still haven't seen a production level numerical weather prediction app written in Rust.
All the time, it is Fortran the government uses for these apps,..."
I vacillate as to whether the best response is: "Who cares?" or "give it time"? First, if C++ actually is better for GUI apps, then more power to C++ (do you have some evidence this is the case?). That doesn't mean their aren't other niches to fill for other languages, like Rust. Next, Rust is a relatively new language. It may end up that it's really great for GUI apps, but again it doesn't have to be. It can be great at other things.
GP mentioned C++ being replaced by Rust - I'd say that a replacement should be as capable as the thing it replaces, so if that's the claim, then Rust should be at the very least OK for GUI apps. If it's not, then that's also okay, but let's not call it a replacement then. :-)
I'm personally excited to see how all those languages will influence each other!
I'm also pretty certain we shouldn't be that pedantic about the word "replacement". Perhaps it's fine for a thing to be a "replacement for the GP" (which I think he/she is pretty clear about) or a "replacement for many uses" or for "all new uses", without being a "complete replacement"?
What's getting so weird about about the tenor of the current anti-Rust backlash is that 1) when the discussion turns to safety, it's "Hey, dude, don't harsh my buzz", but 2) when the discussion turns on the what the person meant, the Rust community's well-founded enthusiasm is interpreted in the harshest, most uncharitable, light.
I don't think I understand - where is any kind of framework mentioned? And even if frameworks were mentioned, I think it's a fair comparison to say "language A has battle-proven / easy-to-use / etc. framework to achieve X, but language B doesn't".
From the moment it can interact with the underlying operating system? C++ doesn't specify any GUI framework as a part of the standard, and yet people manage to write GUI apps. Rust should have the same capabilities of calling into the OS, but GUI apps seem to be slow to appear there - it may be because it's still early days, or because Rust isn't super pleasant to write GUI apps in.
All the time, it is Fortran the government uses for these apps,..."
I vacillate as to whether the best response is: "Who cares?" or "give it time"? First, if C++ actually is better for GUI apps, then more power to C++ (do you have some evidence this is the case?). That doesn't mean their aren't other niches to fill for other languages, like Rust. Next, Rust is a relatively new language. It may end up that it's really great for GUI apps, but again it doesn't have to be. It can be great at other things.