Add tests for From<Vec<_>> and From<[_]>.

Author: c0gent

lib.rs

@@ -1566,6 +1566,31 @@ pub mod tests {
     fn test_from() {
         assert_eq!(&SmallVec::<[u32; 2]>::from(&[1][..])[..], [1]);
         assert_eq!(&SmallVec::<[u32; 2]>::from(&[1, 2, 3][..])[..], [1, 2, 3]);
+
+        let vec = vec![];
+        let small_vec: SmallVec<[u8; 3]> = SmallVec::from(vec);
+        assert_eq!(&*small_vec, &[]);
+        drop(small_vec);
+
+        let vec = vec![1, 2, 3, 4, 5];
+        let small_vec: SmallVec<[u8; 3]> = SmallVec::from(vec);
+        assert_eq!(&*small_vec, &[1, 2, 3, 4, 5]);
+        drop(small_vec);
+
+        let vec = vec![1, 2, 3, 4, 5];
+        let small_vec: SmallVec<[u8; 1]> = SmallVec::from(vec);
+        assert_eq!(&*small_vec, &[1, 2, 3, 4, 5]);
+        drop(small_vec);
+
+        let array = [1];
+        let small_vec: SmallVec<[u8; 1]> = SmallVec::from(array);
+        assert_eq!(&*small_vec, &[1]);
+        drop(small_vec);
+
+        let array = [99; 128];
+        let small_vec: SmallVec<[u8; 128]> = SmallVec::from(array);
+        assert_eq!(&*small_vec, vec![99u8; 128].as_slice());
+        drop(small_vec);
     }
 
     #[test]