wrote first bit of matrix

matrix/src/lib.rs

@@ -1,7 +1,45 @@
+use std::ops::Index;
+
+pub struct Matrix {
+    matrix: Vec<Vec<f32>>,
+}
+
+impl Matrix {
+    pub fn new(matrix: Vec<Vec<f32>>) -> Matrix {
+        Matrix {
+            matrix: matrix,
+        }
+    }
+}
+
+impl Index<usize> for Matrix {
+    type Output = Vec<f32>;
+    fn index(&self, index: usize) -> &Self::Output {
+        &self.matrix[index]
+    }
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        assert_eq!(2 + 2, 4);
+        let m = vec![
+            vec![1.0, 2.0, 3.0, 4.0],
+            vec![5.5, 6.5, 7.5, 8.5],
+            vec![9.0, 10.0, 11.0, 12.0],
+            vec![13.5, 14.5, 15.5, 16.5],
+        ];
+
+        let matrix = Matrix::new(m);
+        assert_eq!(1.0, matrix[0][0]);
+        assert_eq!(4.0, matrix[0][3]);
+        assert_eq!(5.5, matrix[1][0]);
+        assert_eq!(7.5, matrix[1][2]);
+        assert_eq!(11.0, matrix[2][2]);
+        assert_eq!(13.5,  matrix[3][0]);
+        assert_eq!(15.5,  matrix[3][2]);
     }
+
 }