Combining else clauses in nested if statements in Rust

Question

Is there an idiomatic way in Rust to do the following:

let z =
    if (condition1) {
        do_something();
        if (condition2) {
            x
        } else {
            y
        }
    } else {
        y
    }

Alternatively:

let z =
    if (condition1 && condition2) {
        do_something();
        x
    } else if (condition1) {
        do_something();
        y
    } else {
        y
    }

Of course, if this was a fully imperative language (and this was in a function), I could combine the two else clauses:

if (condition1) {
    do_something();
    if (condition2) {
        return x;
    }
}

return y;

But I cannot use:

let z =
{
    if (condition1) {
        do_something();
        if (condition2) {
            return x;
        }
    }

    return y;
}

But since both the inner and the outer if statement (for the first example) must evaluate to an object of whatever type T is and cannot evaluate to (), that doesn't seem possible to use in all cases, for example, when you are defining a variable by the evaluation of the if-statement. Is there a better way?

Answer 1

You can use a closure

let z = (|| {
    if condition1 {
        do_something();
        if condition2 {
            return x;
        }
    };
    y 
})();

Answer 2

You could use a loop with a break value:

let z = loop {
    if condition1 {
        do_something();
        if condition2 {
            break x;
        }
    }

    break y;
};

There is an RFC open now about allowing regular blocks to do that to avoid this kind of never looping loop.