From: Simon Sticko <simon@sticko.se>
Date: Thu, 7 Apr 2022 07:11:58 +0000 (+0200)
Subject: Define Quadrature<0>::SubQuadrature as Quadrature<0>
X-Git-Tag: v9.4.0-rc1~329^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F13600%2Fhead;p=dealii.git

Define Quadrature<0>::SubQuadrature as Quadrature<0>

Before this, the SubQuadrature of Quadrature<0> was defined as
Quadrature<-1>. This can lead to problems with some compilers because
Quadrature<-1> should never be instantiated. Avoid this by redefining
SubQuadrature of Quadrature<0>.
---

diff --git a/include/deal.II/base/quadrature.h b/include/deal.II/base/quadrature.h
index 475229341d..effb96ad2f 100644
--- a/include/deal.II/base/quadrature.h
+++ b/include/deal.II/base/quadrature.h
@@ -88,9 +88,10 @@ class Quadrature : public Subscriptor
 public:
   /**
    * Define an alias for a quadrature that acts on an object of one dimension
-   * less. For cells, this would then be a face quadrature.
+   * less. For cells, this would then be a face quadrature. A sub quadrature of
+   * a 0-dimensional quadrature is defined as still being 0-dimensional.
    */
-  using SubQuadrature = Quadrature<dim - 1>;
+  using SubQuadrature = Quadrature<dim == 0 ? 0 : dim - 1>;
 
   /**
    * Constructor.
@@ -483,7 +484,8 @@ Quadrature<dim>::serialize(Archive &ar, const unsigned int)
 template <>
 Quadrature<0>::Quadrature(const unsigned int);
 template <>
-Quadrature<0>::Quadrature(const Quadrature<-1> &, const Quadrature<1> &);
+Quadrature<0>::Quadrature(const Quadrature<0>::SubQuadrature &,
+                          const Quadrature<1> &);
 template <>
 Quadrature<0>::Quadrature(const Quadrature<1> &);
 template <>