Because you would rather pay the ongoing cost of writing (and worse, having to read) thousands of pointless `if err != nil` blocks than take three minutes to see exactly what try! does, which is (almost) exactly the Rust equivalent of just that.

> That's trivially possible in the Go version

It's also trivially possible in the Rust version, except you don't pay a ludicrous cost in readability of the logic flow in the thousands of other places you have to return an error.

It takes more effort to wrap a handler for a specific exception because there was no need originally to write a handler in that place.

You can just map your logging in between:

foo().map_err(|e| {log(e); e}).bar()

You can just macroexpand ? and do that (although I don't know that there are tools doing macroexpansion currently).

> I don't know what ? really does

It's really nothing special, `a?` simply expands to:

    match a {
        Ok(val) => val,
        Err(err) => {
            return Err(From::from(err))
        }
    }

?

Ok, that's what I expected

> ?

I meant if I have foo().bar() in C# or Java and foo() throws it's equally hard to change the code to add error handling in between since I would need to add a try/catch clause and rethrow the error.