Re: let mut x: int = 1;
You are really missing my point and are burying yourself in small details.
const simply indicates: 1. that the compiler must check the value does not change, and 2. that the compiler can assume the value does not change (as opposed to a const volatile).
In most cases, const brings nothing, because the compiler should be smart enough to see this is a const (please note the "should"), or infer it is a constexpr (which would be more suitable than your suggestion of using const), etc.
The same applies with int. Here, we know the literal is 1, therefore an int by default, unless I set it explicitly to be different, e.g. "1." or "1.f".
We also know I am declaring a variable called x, it's kind of obvious, so why having "let".
My view is that whole thing could be written a "x = 1;" and nothing more, like in Python (we still have the ";" though).
Fixing the mutability does not add much to the code in that case, because if it was "immutable", and decided to make it mutable, we would simply removed the const... so, let's not have it in the first place (for some reason, I believe (some) very old C compiler were accepting i = 1, and assume the type was int if it was not declared).
Now, about Rust...
The language is so verbose, that many people unwrap like crazy anyway.
Panicking on integer overflow in debug mode is overkill because integer arithmetic is well know from the beginning of time for a i8, 255+1=0 (by the way, I like i8, s8, ... f32, f64, as I used to with those in C and C++).
If you really want to do check overflow, or have "clamped types" (255+1=255, 0-1=0), it would be better off adding new types with a specific arithmetic and a specifically defined behaviour, rather than changing what the excepted "machine" behaviour, and avoid inconsistency between debug and release.
Another stuff that annoyed/annoys me was [from memory] std::Rc allowing some construct and later on throwing an exception because there was a circular reference. Talk about safety to build a program, testing it, and having, maybe, at runtime, an exception because the data were visited differently (note: I can't remember what displease Rust, but I found a way to avoid it, and was not impressed by the panic which had not rationale).
My view on Rust is that it has nice things, such as macros, a good amount a libraries, however, I find Rust too verbose to be productive, and the "absolute safety promise" is not true (it's better though).
I would rather have a language which superb type inference or other bits I can't think of at the top of my head right now.
I don't think having a native Linux module (for default of a better word) is going to be key selling point, or seen as a massive achievement, by most of the people outside the hardcore Rust backers.
Biting the hand that feeds IT
