Quicker feedback. It'll tell you in-line the issue (if any) is with your code as soon as you save the file. cargo will tell you the same thing but it takes long

Quicker feedback. It'll tell you in-line the issue (if any) is with your code as soon as you save the file. cargo will tell you the same thing but it takes longer. In addition, this provides type annotations inline and other IDE features like go-to-definition and find-usages.