fix constructor to pass Vec

Author: yuk1ty

Diff for: chapter3/src/3_7/multi_reader.rs

@@ -1,19 +1,13 @@
-use std::{
-    collections::VecDeque,
-    io::{copy, stdout, Read},
-};
+use std::io::{copy, stdout};
 
 use lib::io::MultiReader;
 
 fn main() -> std::io::Result<()> {
     let header = "---- HEADER ----\n".as_bytes();
     let content = "Example of MultiReader\n".as_bytes();
     let footer = "---- FOOTER ----\n".as_bytes();
-    let mut multi_reader = MultiReader::new(VecDeque::from(vec![
-        Box::new(header) as Box<dyn Read>,
-        Box::new(content) as Box<dyn Read>,
-        Box::new(footer) as Box<dyn Read>,
-    ]));
+    let mut multi_reader =
+        MultiReader::new(vec![Box::new(header), Box::new(content), Box::new(footer)]);
     copy(&mut multi_reader, &mut stdout())?;
 
     Ok(())

Diff for: lib/src/io/multi_reader.rs

@@ -6,36 +6,34 @@ use std::{collections::VecDeque, io::Read};
 /// # Example
 ///
 /// ```
-/// use std::{
-///     collections::VecDeque,
-///     io::{copy, stdout, Read},
-/// };
+/// use std::io::{copy, stdout};
 /// use lib::io::MultiReader;
 ///
 /// fn main() -> std::io::Result<()> {
 ///     let header = "---- HEADER ----\n".as_bytes();
 ///     let content = "Example of MultiReader\n".as_bytes();
 ///     let footer = "---- FOOTER ----\n".as_bytes();
-///     let mut multi_reader = MultiReader::new(VecDeque::from(vec![
-///         Box::new(header) as Box<dyn Read>,
-///         Box::new(content) as Box<dyn Read>,
-///         Box::new(footer) as Box<dyn Read>,
-///     ]));
+///     let mut multi_reader =
+///         MultiReader::new(vec![Box::new(header), Box::new(content), Box::new(footer)]);
 ///     copy(&mut multi_reader, &mut stdout())?;
 ///     Ok(())
 /// }
 /// ```
 pub struct MultiReader {
     readers: VecDeque<Box<dyn Read>>,
-    /// Points to where we read right now.
+    /// Points to current element while reading.
     current: Option<Box<dyn Read>>,
 }
 
 impl MultiReader {
-    /// Creates `MultiReader`. `pos` is set to 0 by default.
-    pub fn new(mut readers: VecDeque<Box<dyn Read>>) -> Self {
-        let current = readers.pop_front();
-        Self { readers, current }
+    /// Constructs `MultiReader`. `current` is set to the first element that is popped out from `VecDeque`.
+    pub fn new(readers: Vec<Box<dyn Read>>) -> Self {
+        let mut deque = VecDeque::from(readers);
+        let current = deque.pop_front();
+        Self {
+            readers: deque,
+            current,
+        }
     }
 }