Change to workers

src/lib.rs

-pub struct ThreadPool;
+use std::thread;
+
+pub struct ThreadPool{
+    workers: Vec<Worker>,
+}
 
 impl ThreadPool {
     pub fn new(size: usize) -> ThreadPool {
         assert!(size > 0);
-        ThreadPool
+
+        let mut workers = Vec::with_capacity(size);
+
+        for id in 0..size {
+            workers.push(Worker::new(id));
+        }
+
+        ThreadPool {
+            workers
+        }
+
     }
 
     pub fn execute<F>(&self, f: F)
         where F: FnOnce() + Send + 'static {
 
+    }
+
+    // pub fn spawn<F, T>(f: F) -> JoinHandle<T> 
+    //     where 
+    //         F: FnOnce() -> T + Send + 'static,
+    //         T: Send + 'static
+    // {
+
+    // }
+
+}
+
+struct Worker {
+    id: usize,
+    thread: thread::JoinHandle<()>,
+}
+
+impl Worker {
+    fn new(id: usize) -> Worker {
+        let thread = thread::spawn(|| {});
+
+        Worker {
+            id,
+            thread,
         }
+    }
 }