From 139bd1751fe13ad4870f212dab9495a76c28623f Mon Sep 17 00:00:00 2001
From: young <young@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 3 Jun 2013 10:33:11 +0000
Subject: [PATCH] Deal kindly with PETSC_USE_COMPLEX in PETScWrappers.

git-svn-id: https://svn.dealii.org/trunk@29737 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/include/deal.II/lac/petsc_vector_base.h |  2 --
 deal.II/source/lac/petsc_vector_base.cc         | 13 +++++++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/deal.II/include/deal.II/lac/petsc_vector_base.h b/deal.II/include/deal.II/lac/petsc_vector_base.h
index 8d6b6c127c..72ec27bfb0 100644
--- a/deal.II/include/deal.II/lac/petsc_vector_base.h
+++ b/deal.II/include/deal.II/lac/petsc_vector_base.h
@@ -504,12 +504,10 @@ namespace PETScWrappers
      */
     real_type norm_sqr () const;
 
-#ifndef PETSC_USE_COMPLEX
     /**
      * Return the mean value of the elements of this vector.
      */
     PetscScalar mean_value () const;
-#endif
 
     /**
      * $l_1$-norm of the vector.
diff --git a/deal.II/source/lac/petsc_vector_base.cc b/deal.II/source/lac/petsc_vector_base.cc
index 268ca13316..a763f0532c 100644
--- a/deal.II/source/lac/petsc_vector_base.cc
+++ b/deal.II/source/lac/petsc_vector_base.cc
@@ -411,10 +411,10 @@ namespace PETScWrappers
 
   // @todo does not build with PETSc complex scalar types.
   // :425:25: error: no match for ‘operator/’ in ‘sum / dealii::PETScWrappers::VectorBase::size()’
-#ifndef PETSC_USE_COMPLEX
   PetscScalar
   VectorBase::mean_value () const
   {
+#ifndef PETSC_USE_COMPLEX
     int ierr;
 
     // We can only use our more efficient
@@ -465,8 +465,17 @@ namespace PETScWrappers
     AssertThrow (ierr == 0, ExcPETScError(ierr));
 
     return mean;
-  }
+
+#else // PETSC_USE_COMPLEX
+  Assert ((false),
+	  ExcMessage ("Your PETSc/SLEPc installation was configured with scalar-type complex "
+		      "but this function is not defined for complex types."));
+
+  // Prevent compiler warning about no return value
+  PetscScalar dummy;
+  return dummy;
 #endif
+  }
 
 
   VectorBase::real_type
-- 
2.39.5