You can absolutely make a complete, featureful program in Rust without naming a single lifetime, or even without dealing with a single reference/borrow.
But Rust is a dramatically smaller language than C++. The various subsets of C++ people usually carve out tend to be focused on particular styles of programming, like “no exceptions” or “no RTTI”. Notably never things like “signed integer overflow is now defined”, or “std::launder() is now unnecessary”.
Discussions about Rust sometimes feel quite pointless because you can be several replies deep with someone before realising that actually they don't know much about the language and their strongly-held opinion is based on vibes.
And I didn't even break out the function chaining, closure and associated lifetime stuff that pervades the Rust GUI libraries.
When I can contrast this to say, ImGui C++:
ImGui::Text("Hello, world %d", 123);
if (ImGui::Button("Save"))
MySaveFunction();
ImGui::InputText("string", buf, IM_ARRAYSIZE(buf));
ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
which looks just slightly above C with classes.
This kind of blindness makes me wonder about what universe the people doing "Well Ackshually" about Rust live in.
Rust very much has an enormous learning curve and it cannot be subsetted to simplify it due to both the language and the extensive usage of libraries via Cargo.
It is what it is--and may or may not be a valid tradeoff. But failing to at least acknowledge that will simply make people wonder about the competence of the people asserting otherwise.
The rust code you pasted doesn't show any lifetime.
The `&f` in your imgui example is equivalent to the `&mut age`.
Are you just comparing the syntax? It just take a couple of hours to learn the syntax by following a tutorial and that `&mut` in rust is the same as `&` in C, not to mention that the compiler error tell you to add the `mut` if it is missing.
Also 0..=120 is much more clear than passing to arguments 0.0f, 1.0f. it makes it obvious what it is while looking at the imgui call it isn't.
But Rust is a dramatically smaller language than C++. The various subsets of C++ people usually carve out tend to be focused on particular styles of programming, like “no exceptions” or “no RTTI”. Notably never things like “signed integer overflow is now defined”, or “std::launder() is now unnecessary”.