I am using `CarrierWave` and find myself doing this all the time:

```
fin = File.open(payload_file_name,'rb')
self.payload = fin
fin.close

```

where `payload` is my `CarrierWave` field. I considered doing:

```
self.payload = File.open(payload_file_name,'rb')

```

but I was concerned it would leave the file open and my app server would eventually run out of file pointers. Is there a Rubyism that will let me assign the return value of a simple block to a variable?