From 59d02d42c9918680fe0f56c10e355c5db576259f Mon Sep 17 00:00:00 2001
From: Arne Morten Kvarving <arne.morten.kvarving@sintef.no>
Date: Tue, 18 May 2021 12:08:32 +0200
Subject: [PATCH] changed: make externalLoadBalancer a namespace scoped symbol

clang get confused and claims there's no explicit instantation
when it's a template member.
---
 ebos/eclgenericcpgridvanguard.cc | 10 ++++------
 ebos/eclgenericcpgridvanguard.hh | 11 ++++++-----
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/ebos/eclgenericcpgridvanguard.cc b/ebos/eclgenericcpgridvanguard.cc
index 9a70a1689..760b52f9d 100644
--- a/ebos/eclgenericcpgridvanguard.cc
+++ b/ebos/eclgenericcpgridvanguard.cc
@@ -52,6 +52,8 @@
 
 namespace Opm {
 
+std::optional<std::function<std::vector<int> (const Dune::CpGrid&)>> externalLoadBalancer;
+
 template<class ElementMapper, class GridView, class Scalar>
 EclGenericCpGridVanguard<ElementMapper,GridView,Scalar>::EclGenericCpGridVanguard()
 {
@@ -102,7 +104,7 @@ void EclGenericCpGridVanguard<ElementMapper,GridView,Scalar>::doLoadBalance_(Dun
         const auto& gridView = grid_->leafGridView();
         unsigned numFaces = grid_->numFaces();
         std::vector<double> faceTrans;
-        int loadBalancerSet = externalLoadBalancer_.has_value();
+        int loadBalancerSet = externalLoadBalancer.has_value();
         grid_->comm().broadcast(&loadBalancerSet, 1, 0);
         if (!loadBalancerSet){
             faceTrans.resize(numFaces, 0.0);
@@ -150,7 +152,7 @@ void EclGenericCpGridVanguard<ElementMapper,GridView,Scalar>::doLoadBalance_(Dun
                     std::vector<int> parts;
                     if (grid_->comm().rank() == 0)
                     {
-                        parts =  (*externalLoadBalancer_)(*grid_);
+                        parts =  (*externalLoadBalancer)(*grid_);
                     }
                     parallelWells = std::get<1>(grid_->loadBalance(handle, parts, &wells, ownersFirst, false, 1));
                 }
@@ -367,10 +369,6 @@ Scalar EclGenericCpGridVanguard<ElementMapper,GridView,Scalar>::computeCellThick
     return zz2-zz1;
 }
 
-template<class ElementMapper, class GridView, class Scalar>
-std::optional<std::function<std::vector<int> (const Dune::CpGrid&)>>
-EclGenericCpGridVanguard<ElementMapper,GridView,Scalar>::externalLoadBalancer_;
-
 #if HAVE_DUNE_FEM
 template class EclGenericCpGridVanguard<Dune::MultipleCodimMultipleGeomTypeMapper<
 Dune::GridView<Dune::Fem::GridPart2GridViewTraits<Dune::Fem::AdaptiveLeafGridPart<Dune::CpGrid, Dune::PartitionIteratorType(4), false>>>,
diff --git a/ebos/eclgenericcpgridvanguard.hh b/ebos/eclgenericcpgridvanguard.hh
index fdae0b428..310c2a14c 100644
--- a/ebos/eclgenericcpgridvanguard.hh
+++ b/ebos/eclgenericcpgridvanguard.hh
@@ -34,6 +34,11 @@
 
 namespace Opm {
 
+/// \brief optional functor returning external load balancing information
+///
+/// If it is set then this will be used during loadbalance.
+extern std::optional<std::function<std::vector<int> (const Dune::CpGrid&)>> externalLoadBalancer;
+
 template<class ElementMapper, class GridView, class Scalar>
 class EclGenericCpGridVanguard {
 protected:
@@ -82,7 +87,7 @@ public:
     /// The information is a vector of integers indication the partition index for each cell id.
     static void setExternalLoadBalancer(const std::function<std::vector<int> (const Dune::CpGrid&)>& loadBalancer)
     {
-        externalLoadBalancer_ = loadBalancer;
+        externalLoadBalancer = loadBalancer;
     }
 
     /*!
@@ -131,10 +136,6 @@ protected:
     std::unique_ptr<CartesianIndexMapper> cartesianIndexMapper_;
     std::unique_ptr<CartesianIndexMapper> equilCartesianIndexMapper_;
 
-    /// \brief optional functor returning external load balancing information
-    ///
-    /// If it is set then this will be used during loadbalance.
-    static std::optional<std::function<std::vector<int> (const Dune::CpGrid&)>> externalLoadBalancer_;
     int mpiRank;
 };