| $ cargo check | |
| Checking hello v0.1.0 (file:///projects/hello) | |
| error[E0433]: failed to resolve: use of undeclared type `ThreadPool` | |
| --> src/main.rs:11:16 | |
| | | |
| 11 | let pool = ThreadPool::new(4); | |
| | ^^^^^^^^^^ use of undeclared type `ThreadPool` | |
| For more information about this error, try `rustc --explain E0433`. | |
| error: could not compile `hello` (bin "hello") due to 1 previous error |