namespace.

This namespace was probably meant to mark implementation details.  However it
led to violations of the ODR (one definition rule), and to warnings about
defined-but-unused functions (see below).

To illustrate the problem consider the function template
Dune::readMatrixMarket:

  template<typename T, typename A, int brows, int bcols>
  void readMatrixMarket(Dune::BCRSMatrix<Dune::FieldMatrix<T,brows,bcols>,A>& matrix,
                        std::istream& istr)
  {
    // ...
    readSparseEntries(matrix, istr, entries, header, NumericWrapper<T>());
  }

The ODR states (§3.2/5):

  There can be more than one definition of a [...] non-static function
  template (14.5.6) [...] in a program provided that each definition appears
  in a different translation unit, and provided the definitions satisfy the
  following requirements.  Given such an entity named D defined in more than
  one translation unit, then

  - each definition of D shall consist of the same sequence of tokens; and

  - in each definition of D, corresponding names, looked up according to 3.4,
    shall refer to an entity defined within the definition of D, or shall
    refer to the same entity, after overload resolution (13.3) and after
    matching of partial template specialization (14.8.3), except that a name
    can refer to a const object with internal or no linkage if the object has
    the same literal type in all definitions of D, and the object is
    initialized with a constant expression (5.19), and the value (but not the
    address) of the object is used, and the object has the same value in all
    definitions of D; and

  [...]

This is violated by e.g. both readSparseEntries, which is defined in the
anonymous namespace.  Since it is not defined within readMatrixMarket, it must
refer to the same entity in all translation units.  However, its name is
effectively Dune::<unique>::readSparseEntries, where <unique> is unique to
each translation unit, and thus it effectively refers to a different entity in
each translation unit, and the program is ill-formed as soon as move than one
translation unit does #include <dune/istl/matrixmarket.hh>.

The warnings by g++-4.9 looked like this:
======================================================================
g++ -std=c++11 -DHAVE_CONFIG_H -I. -I../../..  -pthread -I/home/joe/Projekte/pdelab-2.4/dune-common -I/home/joe/Projekte/pdelab-2.4/dune-common -I../../.. -I/usr/lib/openmpi/include -I/usr/lib/openmpi/include/openmpi -pthread -DMPIPP_H -DENABLE_MPI=1   -g -O3 -Wall -MT matrixmarkettest-matrixmarkettest.o -MD -MP -MF .deps/matrixmarkettest-matrixmarkettest.Tpo -c -o matrixmarkettest-matrixmarkettest.o `test -f 'matrixmarkettest.cc' || echo './'`matrixmarkettest.cc
[...]
In file included from matrixmarkettest.cc:11:0:
../../../dune/istl/matrixmarket.hh:501:10: warning: ‘void Dune::{anonymous}::readNextLine(std::istream&, std::ostringstream&, Dune::{anonymous}::LineType&)’ defined but not used [-Wunused-function]
     void readNextLine(std::istream& file, std::ostringstream&, LineType& type)
          ^
In file included from matrixmarkettest.cc:11:0:
../../../dune/istl/matrixmarket.hh:601:19: warning: ‘std::istream& Dune::{anonymous}::operator>>(std::istream&, Dune::{anonymous}::NumericWrapper<Dune::{anonymous}::PatternDummy>&)’ defined but not used [-Wunused-function]
     std::istream& operator>>(std::istream& is, NumericWrapper<PatternDummy>& num)
                   ^
======================================================================

The function is in an anonymous namespace, and it is used nowhere inside
dune-istl.

The standard states (8.3.6/4) that adding default arguments in later
function declarations are only valid for non-template functions.
In matrixmarket.hh, the function template loadMatrixMarket is declared
and a default argument for the last parameter is provided. In
owneroverlapcopy.hh, OwnerOverlapCopyCommunication contains a friend
declaration of loadMatrixMarket without the default parameter. If now
owneroverlapcopy.hh is included before matrixmarket.hh, the friend
declaration is the first declaration and the default parameter in
matrixmarket.hh is invalid.
By including matrixmarket.hh in owneroverlapcopy.hh, we make sure that
the declaration which provides the default argument is always the first
one.

This test actually does test the parallel functionality
that is now contained in dune-common for quite some time.
While it is using BlockVector this is not needed by the test.
It works with any container supporting operator[].

Therefore this commit gets rid of BlockVector and uses std::vector
instead. This will allow us to move the test to dune-core subsequently.

Previously, we assumed that if a_{ij} is stored in the sparse matrix
then a_{ji} must be stored also and used mat[i][j] to access. If the entry
was not stored then an exception somewhere in basearray.hh was thrown.
Unfortunately knowing the cause for this exception is insider knowledge,
seldomly leaked ;). In addition there is now reason to throw an expection here.

With this commit we the find method on the row to search for the entry a_{ji}.
If it is not present we simply treat it as being zero.

Fixes FS#FS#1649.

extended the amgtest to also use field_type = complex by switching the
definition of XREAL

instead of just returning the real part, we return csgn(v)*abs(v). For real values this is
equivalent to returning v.

a) add the appropriate typedefs for real_type
b) update the norm implementations to return real_type
c) change all variables assigned from norm_(...) to real_type

we have to retrieve an int which is stored in field_type. If the field_type is std::complex, we
have to access the real-component, if it is double/float, we don't have to do anything
special. We use std::real(.) to get the correct real value. This function (with its appropriate
overloads) is available from c++11 on, but this part was already supported by the ancient
g++ version we supprt ;-)

on fedora 21, the default subdirectory for SuperLU includes is
called "SuperLU".

Emmanouil Kiagias authored 10 years ago and Christoph Grüninger committed 10 years ago

Updated how METIS_PartGraphRecursive is called in METIS version 5.
In the new parameters NULL value is used where possible. Only one
new parameter could not be set to NULL, it is the "ncon" (second argument).
In the manual it says: "ncon: The number of balancing constraints.
It should be at least 1." so 1 is used as its value.

Also options with the new layout are passed in METIS_PartGraphRecursive
initialized with the default values(default values also used in the
current code: options[0]=0). Only one option was added manually:
the METIS_OPTION_NUMBERING = numflag which is the same numflag parameter
passed in the old version of METIS_PartGraphRecursive function.

Signed-off-by: Christoph Grüninger <gruenich@dune-project.org>

On request of Markus Blatt.  Supposedly there have been problems with and/or on
older compilers.

When DUNE_ISTL_WITH_CHECKING is enabled, the BCRSMatrix throws an
exception when trying to access a row that has no columns. This creates
a problem in PDELab when using nested BCRSMatrices (as some people do
for operator splitting in PDELab), where an off-diagonal BCRSMatrix
block might be completely empty (i.e. have a correctly set up structure,
but every row in the off-diagonal BCRSMatrix is empty. If the PDELab
assembler then attempts to set a Dirichlet constraint, it has to access
the row to set all columns in that row to zero, but the check in
operator[] prevents it from doing so.

So this patch just drops that check.

This patch removes the assumption that the field_type and / or real_type
can always be implicitly converted to double and can be implicitly
constructed from an int (in constructs like field_type d = 0;).

This patch is required for compatibility with the FLOP counter in PDELab.

It belongs to dune-common's config.h.cmake. Otherwise
it cannot be shared with other modules using ParMETIS.

It should be std::endl.
Courtesy of GCC 5-svn, it refuses to compile these.

While c++11 allows a trailing comma in enums,
we should avoid this because it provokes
gcc-4.4 warnings.

The check gets removed from dune-common, thus ISTL has to call it itself.