grep for a line in a file then remove the line

$ cat example.txt

Yields:

example
test
example

I want to remove 'test' string from this file.

$ grep -v test example.txt > example.txt 
$ cat example.txt 
$

The below works, but I have a feeling there is a better way!

$ grep -v test example.txt > example.txt.tmp;mv example.txt.tmp example.txt 
$ cat example.txt 
example
example

Worth noting that this is going to be on a file with over 10,000 lines.

Cheers