From d808f04f6a3975f8f56b9c1112b0dc5ec401e360 Mon Sep 17 00:00:00 2001
From: Timo Heister <timo.heister@gmail.com>
Date: Fri, 20 Sep 2019 10:13:17 -0400
Subject: [PATCH] instantiate TensorProductPolynomials for dim=0

---
 .../deal.II/base/tensor_product_polynomials.h |  3 ++-
 source/base/scalar_polynomials_base.cc        |  1 +
 source/base/tensor_product_polynomials.cc     | 26 ++++++++++++-------
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/include/deal.II/base/tensor_product_polynomials.h b/include/deal.II/base/tensor_product_polynomials.h
index 28f7c9d036..546904b53f 100644
--- a/include/deal.II/base/tensor_product_polynomials.h
+++ b/include/deal.II/base/tensor_product_polynomials.h
@@ -410,7 +410,8 @@ private:
    * <tt>i</tt>.
    */
   void
-  compute_index(const unsigned int i, unsigned int (&indices)[dim]) const;
+  compute_index(const unsigned int i,
+                unsigned int (&indices)[(dim > 0 ? dim : 1)]) const;
 
   /**
    * Given the input to the constructor, compute <tt>n_pols</tt>.
diff --git a/source/base/scalar_polynomials_base.cc b/source/base/scalar_polynomials_base.cc
index c067980ed4..8eedfaf6da 100644
--- a/source/base/scalar_polynomials_base.cc
+++ b/source/base/scalar_polynomials_base.cc
@@ -35,6 +35,7 @@ ScalarPolynomialsBase<dim>::ScalarPolynomialsBase(
 
 
 
+template class ScalarPolynomialsBase<0>;
 template class ScalarPolynomialsBase<1>;
 template class ScalarPolynomialsBase<2>;
 template class ScalarPolynomialsBase<3>;
diff --git a/source/base/tensor_product_polynomials.cc b/source/base/tensor_product_polynomials.cc
index 49ce046c0d..7db3763f10 100644
--- a/source/base/tensor_product_polynomials.cc
+++ b/source/base/tensor_product_polynomials.cc
@@ -98,7 +98,7 @@ void
 TensorProductPolynomials<dim, PolynomialType>::output_indices(
   std::ostream &out) const
 {
-  unsigned int ix[dim];
+  unsigned int ix[(dim > 0) ? dim : 1];
   for (unsigned int i = 0; i < this->n(); ++i)
     {
       compute_index(i, ix);
@@ -164,7 +164,7 @@ TensorProductPolynomials<dim, PolynomialType>::compute_grad(
   const unsigned int i,
   const Point<dim> & p) const
 {
-  unsigned int indices[dim];
+  unsigned int indices[(dim > 0) ? dim : 1];
   compute_index(i, indices);
 
   // compute values and
@@ -201,7 +201,7 @@ TensorProductPolynomials<dim, PolynomialType>::compute_grad_grad(
   const unsigned int i,
   const Point<dim> & p) const
 {
-  unsigned int indices[dim];
+  unsigned int indices[(dim > 0) ? dim : 1];
   compute_index(i, indices);
 
   double v[dim][3];
@@ -433,8 +433,9 @@ AnisotropicPolynomials<dim>::AnisotropicPolynomials(
 
 template <int dim>
 void
-AnisotropicPolynomials<dim>::compute_index(const unsigned int i,
-                                           unsigned int (&indices)[dim]) const
+AnisotropicPolynomials<dim>::compute_index(
+  const unsigned int i,
+  unsigned int (&indices)[(dim > 0 ? dim : 1)]) const
 {
 #ifdef DEBUG
   unsigned int n_poly = 1;
@@ -443,7 +444,10 @@ AnisotropicPolynomials<dim>::compute_index(const unsigned int i,
   Assert(i < n_poly, ExcInternalError());
 #endif
 
-  if (dim == 1)
+  if (dim == 0)
+    {
+    }
+  else if (dim == 1)
     internal::compute_tensor_index(i,
                                    polynomials[0].size(),
                                    0 /*not used*/,
@@ -462,7 +466,7 @@ double
 AnisotropicPolynomials<dim>::compute_value(const unsigned int i,
                                            const Point<dim> & p) const
 {
-  unsigned int indices[dim];
+  unsigned int indices[(dim > 0) ? dim : 1];
   compute_index(i, indices);
 
   double value = 1.;
@@ -478,7 +482,7 @@ Tensor<1, dim>
 AnisotropicPolynomials<dim>::compute_grad(const unsigned int i,
                                           const Point<dim> & p) const
 {
-  unsigned int indices[dim];
+  unsigned int indices[(dim > 0) ? dim : 1];
   compute_index(i, indices);
 
   // compute values and
@@ -506,7 +510,7 @@ Tensor<2, dim>
 AnisotropicPolynomials<dim>::compute_grad_grad(const unsigned int i,
                                                const Point<dim> & p) const
 {
-  unsigned int indices[dim];
+  unsigned int indices[(dim > 0) ? dim : 1];
   compute_index(i, indices);
 
   std::vector<std::vector<double>> v(dim, std::vector<double>(3));
@@ -601,7 +605,7 @@ AnisotropicPolynomials<dim>::evaluate(
       // one-dimensional indices of
       // this particular tensor
       // product polynomial
-      unsigned int indices[dim];
+      unsigned int indices[(dim > 0) ? dim : 1];
       compute_index(i, indices);
 
       if (update_values)
@@ -706,6 +710,7 @@ AnisotropicPolynomials<dim>::clone() const
 
 
 /* ------------------- explicit instantiations -------------- */
+template class TensorProductPolynomials<0, Polynomials::Polynomial<double>>;
 template class TensorProductPolynomials<1, Polynomials::Polynomial<double>>;
 template class TensorProductPolynomials<2, Polynomials::Polynomial<double>>;
 template class TensorProductPolynomials<3, Polynomials::Polynomial<double>>;
@@ -720,6 +725,7 @@ template class TensorProductPolynomials<
   3,
   Polynomials::PiecewisePolynomial<double>>;
 
+template class AnisotropicPolynomials<0>;
 template class AnisotropicPolynomials<1>;
 template class AnisotropicPolynomials<2>;
 template class AnisotropicPolynomials<3>;
-- 
2.39.5