> languages where "trivial" things "just require" rapidly become "not so trivial" in the aggregate
Sure. And in C and Zig, it's "trivial" to make a global mutable variable, it "just requires" you to flawlessly uphold memory access invariants manually across all possible concurrent states of your program.
Stop beating around the bush. Rust is just easier than nearly any other language for writing concurrent programs, and it's not even close (though obligatory shout out to Erlang).
Is it easier than golang?
No it doesn't. Zig doesn't require you to think about concurrency at all. You can just not do concurrency.
> Stop beating around the bush. Rust is just easier than nearly any other language for writing concurrent programs
This is entirely unrelated to the problem of defining shared global state.
There. I defined shared global state without caring about writing concurrent programs.Rust (and you) makes an assertion that all code should be able to run in a concurrent context. Code that passes that assertion may be more portable than code that does not.
What is important for you to understand is: code can be correct under a different set of assertions. If you assert that some code will not run in a concurrent environment, it can be perfectly correct to create a mutable global variable. And this assertion can be done implicitly (ie: I wrote the program knowing I'm not spawning any threads, so I know this variable will not have shared mutable access).