Update tests and add is_empty for Mat.

src/mat.rs

@@ -18,6 +18,10 @@ impl<T> Mat<T> {
         assert_eq!(vec.len(), m * n);
         Self { m, n, inner: vec }
     }
+    /// Check if the [Mat] is empty.
+    pub fn is_empty(&self) -> bool {
+        self.m == 0 || self.n == 0
+    }
 }
 
 impl<T> Mat<T> {

tests/stdin.rs

@@ -1,4 +1,4 @@
-use iof::{read_n, try_read_n};
+use iof::{read_array, read_m_n, read_n, try_read_array, try_read_m_n, try_read_n, Mat};
 use std::{
     io::Write,
     process::{Command, Stdio},
@@ -24,9 +24,25 @@ fn dot_product() {
 }
 
 #[test]
-fn read_0() {
+fn read_n_0() {
     let s1: Vec<usize> = read_n(0);
     let s2: Vec<char> = try_read_n(0).unwrap();
     assert!(s1.is_empty());
     assert!(s2.is_empty());
 }
+
+#[test]
+fn read_m_n_0_0() {
+    let s1: Mat<usize> = read_m_n(0, 1);
+    let s2: Mat<char> = try_read_m_n(1, 0).unwrap();
+    assert!(s1.is_empty());
+    assert!(s2.is_empty());
+}
+
+#[test]
+fn read_array_0() {
+    let s1: [usize; 0] = *read_array();
+    let s2: [char; 0] = *try_read_array().unwrap();
+    assert!(s1.is_empty());
+    assert!(s2.is_empty());
+}