# Error code E0727

A `yield` clause was used in an `async` context.

Erroneous code example:

    #![feature(coroutines)]

    fn main() {
        let coroutine = || {
            async {
                yield;
            }
        };
    }

Here, the `yield` keyword is used in an `async` block, which is not yet supported.

To fix this error, you have to move `yield` out of the `async` block:

    #![feature(coroutines)]

    fn main() {
        let coroutine = || {
            yield;
        };
    }