Implemented fs::metadata and Path::exists

src/fs/metadata.rs

@@ -1,8 +1,7 @@
-use std::path::Path;
-
 use cfg_if::cfg_if;
 
 use crate::io;
+use crate::path::Path;
 use crate::task::blocking;
 
 /// Reads metadata for a path.
@@ -36,7 +35,7 @@ use crate::task::blocking;
 /// # Ok(()) }) }
 /// ```
 pub async fn metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
-    let path = path.as_ref().to_owned();
+    let path: std::path::PathBuf = path.as_ref().to_path_buf().into();
     blocking::spawn(async move { std::fs::metadata(path) }).await
 }
 

src/path/path.rs

@@ -75,6 +75,31 @@ impl Path {
         self.inner.components()
     }
 
+    /// Returns `true` if the path points at an existing entity.
+    ///
+    /// This function will traverse symbolic links to query information about the
+    /// destination file. In case of broken symbolic links this will return `false`.
+    ///
+    /// If you cannot access the directory containing the file, e.g., because of a
+    /// permission error, this will return `false`.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use async_std::path::Path;
+    /// assert_eq!(Path::new("does_not_exist.txt").exists(), false);
+    /// ```
+    ///
+    /// # See Also
+    ///
+    /// This is a convenience function that coerces errors to false. If you want to
+    /// check errors, call [fs::metadata].
+    ///
+    /// [fs::metadata]: ../fs/fn.metadata.html
+    pub async fn exists(&self) -> bool {
+        fs::metadata(self).await.is_ok()
+    }
+
     /// Directly wraps a string slice as a `Path` slice.
     ///
     /// This is a cost-free conversion.