Fix compliation issues with cxx20 standard.

See merge request core/dune-common!866

header cast.h

Rewrite FindMETIS to provide imported targets

See merge request core/dune-common!821

Simon Praetorius authored May 23, 2020 and Christoph Grüninger committed Sep 26, 2020

Provide imported target METIS::METIS and version detection.
Allow Scotch to be used as library wrapper, activated by ENABLE_SCOTCH_METIS.
Detect the API version of the Scotch wrapper using SCOTCH_METIS_VERSION hint.
Add metistest.

change find_dependenty to find_package(QUIET) in FindSuietsparse

See merge request core/dune-common!861

Some cleanup of FindPTScotch

See merge request core/dune-common!860

Feature/cmake improvments

See merge request core/dune-common!856

[cmake] Remove incomplete CPack support

See merge request core/dune-common!853

It was never used to make an official build or tarball.

[MPI] fix violation of one-definition-rule in GuardCommunicator

See merge request core/dune-common!827

[cmake] build pdf during install

Closes #191

See merge request core/dune-common!852

kudos to @edscott.wilson

Bugfix for class import python/c++

See merge request core/dune-common!849

add missing 'pragma once' to generated python modules

bug fix

bug fix

bug fix

- improve export of single class (added base and other options)
- bug fix in 'Method' class

remove value-return statement in void-function

See merge request core/dune-common!847

[cleanup][builder] remove syntax warning.

See merge request core/dune-common!845

Fetch default yml files via different project instead of url

See merge request core/dune-common!841

This is a workaround for a bug that showed up after gitlab migration. See issue
infrastructure/issues0#62 for further
discussion.

Merge branch 'fix-eigenvectors-some-more' into 'master'

ref:core/dune-common\> This merge request fixes three bugs in the
eigenvalue/eigenvector code for 2x2 and 3x3 symmetric matrices. Surprisingly,
all three bugs can be triggered by using particular diagonal matrices.

See merge request [core/dune-common!839]

  [core/dune-common!839]: gitlab.dune-project.org/core/dune-common/merge_requests/839

Add a test for the 2x2 zero matrix as well, even though that
appears to work properly.

The code for eigenvalues of diagonal 3x3 matrices didn't take
the matrix scaling properly into account.

Surprising how difficult it is to compute eigenvalues of
diagonal matrices...

The eigenvector code used to fail for certain seemingly simple
diagonal 2x2 matrices.  The reason was that the code tried
to avoid certain all-zero matrix columns by testing whether
the norm is (close to) zero.  That proved to be surprisingly
unstable.  The fix here is simple: Pick the column with the
larger column norm (we know they are not both zero).

Also add a test case to make sure the bug is gone.

Merge branch 'feature/find_ptscotch' into 'master'

ref:core/dune-common\>

### Summary

This is a small improvement of the existing FindPTScotch cmake module. It
allows to search only for Scotch or PTScotch and thus it is possible to use
Scotch without PTScotch or if no MPI is available.

See merge request [core/dune-common!831]

  [core/dune-common!831]: gitlab.dune-project.org/core/dune-common/merge_requests/831

Merge branch 'eigenvalues-of-singular-matrices' into 'master'

ref:core/dune-common\> The eigenvector algorithm for symmetric FieldMatrices
was buggy, it does not handle singular matrices well. Add a test and fix the
bug.

See merge request [core/dune-common!836]

  [core/dune-common!836]: gitlab.dune-project.org/core/dune-common/merge_requests/836

Plus, add a test that eigenvalues and eigenvectors are not NaN.
The previous test would not actually catch this, because
"NaN > some_number" is always false.

The eigenvectors were correct, but their ordering didn't match
the one of the eigenvalues.

And document the algorithm while we are there.

Merge branch 'feature/sparseRange' into 'master'

ref:core/dune-common\> This helper allows to use for-loops with structured
bindings for sparse ranges R whose iterators it provide an it->index() method,
like this

    for(auto&& [A_i, i] : sparseRange(R))
      doSomethingWithValueAndIndex(A_i, i);

This also adds a test and fixes the placement of the range-utilities in the
appropriate doxygen group to make them easier to discover.

See merge request [core/dune-common!834]

  [core/dune-common!834]: gitlab.dune-project.org/core/dune-common/merge_requests/834