diff --git a/lion/foundation/types.h b/lion/foundation/types.h
index 1f3f1b7..3a141e5 100644
--- a/lion/foundation/types.h
+++ b/lion/foundation/types.h
@@ -10,4 +10,11 @@ using std::size_t;
 using std::max;
 using std::min;
 
+
+#ifdef _MSC_VER
+#define windows_local_constexpr_auto static constexpr auto
+#else
+#define windows_local_constexpr_auto constexpr auto
+#endif
+
 #endif
diff --git a/lion/foundation/utils.hpp b/lion/foundation/utils.hpp
index 7719017..ff4f9aa 100644
--- a/lion/foundation/utils.hpp
+++ b/lion/foundation/utils.hpp
@@ -798,6 +798,11 @@ std::vector<ScalarType> grid_vectors2points_rowmaj(const ContainerOfGridVectorsT
     //               0, 4, 6,
     //               1, 4, 6 }".
     //
+    // Note that the "rows" of points are ordered in
+    // column-major order w.r.t. to the grid (i.e.,
+    // first dimension advances first, then the second,
+    // etc).
+    //
 
     const auto num_grid_vectors = grid_vectors.size();
 
diff --git a/lion/math/polynomial.h b/lion/math/polynomial.h
index 60a541b..bf2d302 100644
--- a/lion/math/polynomial.h
+++ b/lion/math/polynomial.h
@@ -517,7 +517,7 @@ inline Polynomial<T> Polynomial<T>::derivative() const
     {
         coeffs[n] = std::vector<T>(_n[n],T());
         for (size_t i = 0; i <= _n[n]; ++i)
-            for (int j = i-1 ; j >= 0; j -= 2)
+            for (std::ptrdiff_t j = static_cast<std::ptrdiff_t>(i) - 1 ; j >= 0; j -= 2)
                 coeffs[n][j] += _coeffs[n][i]*(2.0*(j+1.0)-1.0);
     
         for (size_t i = 0; i < _n[n]; ++i)