Make VectorBase::operator= private and undefined.

This operator was formerly implicitly defined, which provides, almost surely,
the wrong behavior since the underlying Vec will then be destroyed twice.

Since both inheriting classes (Vector and MPI::Vector) define their own
operator= overloads this operator is also not necessary.

diff --git a/doc/news/changes/incompatibilities/20170211DavidWells b/doc/news/changes/incompatibilities/20170211DavidWells
new file mode 100644 (file)
index 0000000..cfb16f0
--- /dev/null
+++ b/doc/news/changes/incompatibilities/20170211DavidWells
@@ -0,0 +1,10 @@
+Changed: PETScWrappers::VectorBase::operator= is now both private and
+undefined. This operator was formerly implicitly defined (i.e., it did a
+byte-for-byte copy of VectorBase's members), which provided, almost certainly,
+the wrong behavior since the underlying <code>Vec</code> (the managed PETSc
+object) would then be destroyed twice. Since both inheriting classes
+(PETScWrappers::Vector and PETScWrappers::MPI::Vector) define their own
+operator= overloads this operator is also not necessary.
+
+<br>
+(David Wells, 2017/02/11)

diff --git a/include/deal.II/lac/petsc_vector_base.h b/include/deal.II/lac/petsc_vector_base.h
index 5be9d803632578b75bbe83dc1560128f681576c7..cf7dac42b421726e77ca351c73b2d395c77d2070 100644 (file)
--- a/include/deal.II/lac/petsc_vector_base.h
+++ b/include/deal.II/lac/petsc_vector_base.h
@@ -801,7 +801,13 @@ namespace PETScWrappers
                                const PetscScalar  *values,
                                const bool         add_values);
 
-
+  private:
+    /**
+     * Assignment operator. This is currently not implemented, so it is
+     * deliberately left as private (and undefined) to prevent accidental
+     * usage.
+     */
+    VectorBase &operator=(const VectorBase &);
   };