Added more testing to instantiate some missing templates.

test/vector2.cpp

@@ -11,7 +11,25 @@ int main()
 {
     Vector2f a(1, 0);
     Vector2f b(0, 1);
-    assert (fabs(a % b - 1.0f) < 1e-5);
+    assert(fabs(a % b - 1.0f) < 1e-5);
+
+    Vector2f c;
+    assert(fabs(c(0) - 0) < 1e-5);
+    assert(fabs(c(1) - 0) < 1e-5);
+
+    Matrix<float, 2, 1> d(a);
+    assert(fabs(d(0,0) - 1) < 1e-5);
+    assert(fabs(d(1,0) - 0) < 1e-5);
+
+    Vector2f e(d);
+    assert(fabs(e(0) - 1) < 1e-5);
+    assert(fabs(e(1) - 0) < 1e-5);
+
+    float data[] = {4,5};
+    Vector2f f(data);
+    assert(fabs(f(0) - 4) < 1e-5);
+    assert(fabs(f(1) - 5) < 1e-5);
+
     return 0;
 }