Piping output from one command into another command

It's there a way of piping the output of a command into another? I'm trying to make this example working. But the `stdin` method expect a type `T: Into` as parameter. The following example would work if I used `std::process::Command`.
```rust
let child = async_std::process::Command::new("ls")
.stdout(async_std::process::Stdio::piped())
.spawn()?;
async_std::process::Command::new("grep")
.arg("a")
.stdin(child.stdout.unwrap())
.spawn()?;
```
I get the following error:

```the trait bound `Stdio: From` is not satisfied [...]```