From 89ea8b434bb7b973e6b7a060c5a54bbda7e70605 Mon Sep 17 00:00:00 2001
From: Stefano Zampini <stefano.zampini@gmail.com>
Date: Tue, 17 Jan 2023 11:07:05 +0300
Subject: [PATCH] PETScWrappers::VectorBase implement copy operator

Judging from 456c02ad25e, this was not implemented
---
 include/deal.II/lac/petsc_vector_base.h | 13 ++++++-------
 source/lac/petsc_vector_base.cc         | 13 +++++++++++++
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/include/deal.II/lac/petsc_vector_base.h b/include/deal.II/lac/petsc_vector_base.h
index 5e84c1e42e..8a5510054d 100644
--- a/include/deal.II/lac/petsc_vector_base.h
+++ b/include/deal.II/lac/petsc_vector_base.h
@@ -279,13 +279,6 @@ namespace PETScWrappers
      */
     explicit VectorBase(const Vec &v);
 
-    /**
-     * The copy assignment operator is deleted to avoid accidental usage with
-     * unexpected behavior.
-     */
-    VectorBase &
-    operator=(const VectorBase &) = delete;
-
     /**
      * Destructor.
      */
@@ -311,6 +304,12 @@ namespace PETScWrappers
     void
     compress(const VectorOperation::values operation);
 
+    /**
+     * The copy assignment operator.
+     */
+    VectorBase &
+    operator=(const VectorBase &);
+
     /**
      * Set all components of the vector to the given number @p s. Simply pass
      * this down to the individual block objects, but we still need to declare
diff --git a/source/lac/petsc_vector_base.cc b/source/lac/petsc_vector_base.cc
index 5998d1894c..b1982975fe 100644
--- a/source/lac/petsc_vector_base.cc
+++ b/source/lac/petsc_vector_base.cc
@@ -189,6 +189,19 @@ namespace PETScWrappers
 
 
 
+  VectorBase &
+  VectorBase::operator=(const VectorBase &v)
+  {
+    Assert(size() == v.size(), ExcDimensionMismatch(size(), v.size()));
+
+    PetscErrorCode ierr = VecCopy(v, vector);
+    AssertThrow(ierr == 0, ExcPETScError(ierr));
+
+    return *this;
+  }
+
+
+
   VectorBase &
   VectorBase::operator=(const PetscScalar s)
   {
-- 
2.39.5