From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Fri, 5 Oct 2018 04:42:23 +0000 (-0600)
Subject: Add a variadic constructor to hp::QCollection.
X-Git-Tag: v9.1.0-rc1~657^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9249e3f07b6fdb361c865d40b6f55b1283eed3fd;p=dealii.git

Add a variadic constructor to hp::QCollection.
---

diff --git a/include/deal.II/hp/q_collection.h b/include/deal.II/hp/q_collection.h
index 8f37004529..7d0b05ebbd 100644
--- a/include/deal.II/hp/q_collection.h
+++ b/include/deal.II/hp/q_collection.h
@@ -62,6 +62,15 @@ namespace hp
      */
     explicit QCollection(const Quadrature<dim> &quadrature);
 
+    /**
+     * Constructor. This constructor creates a QCollection from one or
+     * more quadrature objects passed to the constructor. For this
+     * call to be valid, all arguments need to be of types derived
+     * from class Quadrature<dim>.
+     */
+    template <class... QTypes>
+    explicit QCollection(const QTypes &... quadrature_objects);
+
     /**
      * Adds a new quadrature rule to the QCollection. In most cases, you will
      * want to add quadrature rules in the same order as the elements were
@@ -136,6 +145,24 @@ namespace hp
 
   /* --------------- inline functions ------------------- */
 
+  template <int dim>
+  template <class... QTypes>
+  QCollection<dim>::QCollection(const QTypes &... quadrature_objects)
+  {
+    static_assert(is_base_of_all<Quadrature<dim>, QTypes...>::value,
+                  "Not all of the input arguments of this function "
+                  "are derived from Quadrature<dim>!");
+
+    // loop over all of the given arguments and add the quadrature objects to
+    // this collection. Inlining the definition of q_pointers causes internal
+    // compiler errors on GCC 7.1.1 so we define it separately:
+    const auto q_pointers = {&quadrature_objects...};
+    for (auto p : q_pointers)
+      push_back(*p);
+  }
+
+
+
   template <int dim>
   inline unsigned int
   QCollection<dim>::size() const