Merge branch 'fix-implicit-this-capture' into 'master'

ref:core/dune-common C++20 deprecates implicit capture of this using [=], and
gcc9 warns about that. Unfortunately, in C++ before 20 listing this together
with a capture-default of = is illegal, and GCC 8 emits a warning about that
that apparently can't be silenced. So the only option if we want to appease
both pre- and post-C++20 is to list each entity to be captures explicitly.
Luckily, that is not too hard in this case.

See [https://gitlab.dune-project.org/core/dune-common/-/jobs/139584\#L486]
(debian:11 gcc-9-20):

    [ 40%] Building CXX object dune/common/CMakeFiles/dunecommon.dir/simd/test.cc.o
    In file included from /builds/core/dune-common/dune/common/simd/test.cc:6:
    /builds/core/dune-common/dune/common/simd/test.hh: In lambda function:
    /builds/core/dune-common/dune/common/simd/test.hh:334:36: warning: implicit capture of 'this' via '[=]' is deprecated in C++20 [-Wdeprecated]
      334 |         Hybrid::forEach(Rebinds{}, [=](auto target) {
          |                                    ^
    /builds/core/dune-common/dune/common/simd/test.hh:334:36: note: add explicit 'this' or '*this' capture

WIP:

-   [x] Check these warnings are really gone in the CI

See merge request [core/dune-common!775]

  [https://gitlab.dune-project.org/core/dune-common/-/jobs/139584\#L486]: https://gitlab.dune-project.org/core/dune-common/-/jobs/139584#L486
  [core/dune-common!775]: gitlab.dune-project.org/core/dune-common/merge_requests/775

C++20 deprecates implicit capture of `this` using `[=]`, and gcc9 warns about
that.  Unfortunately, in C++ before 20 listing `this` together with a
capture-default of `=` is illegal, and GCC 8 emits a warning about that that
apparently can't be silenced.  So the only option if we want to appease both
pre- and post-C++20 is to list each entity to be captures explicitly.
Luckily, that is not too hard in this case.

See https://gitlab.dune-project.org/core/dune-common/-/jobs/139584#L486
(debian:11 gcc-9-20):
```
[ 40%] Building CXX object dune/common/CMakeFiles/dunecommon.dir/simd/test.cc.o
In file included from /builds/core/dune-common/dune/common/simd/test.cc:6:
/builds/core/dune-common/dune/common/simd/test.hh: In lambda function:
/builds/core/dune-common/dune/common/simd/test.hh:334:36: warning: implicit capture of 'this' via '[=]' is deprecated in C++20 [-Wdeprecated]
  334 |         Hybrid::forEach(Rebinds{}, [=](auto target) {
      |                                    ^
/builds/core/dune-common/dune/common/simd/test.hh:334:36: note: add explicit 'this' or '*this' capture
```

Merge branch 'fix-warning-add-comments' into 'master'

ref:core/dune-common This is a regression test, the threw up undefined
variable warnings. unsure about the correct fix, I tried to understand the
test. In addition to fixing the warnings, I left some comments too, in the
hope future readers will have a little easier time understanding what it is
supposed to do.

The warnings showed up in
[https://gitlab.dune-project.org/core/dune-common/-/jobs/139437\#L665]
(debian:10 clang-7-libcpp-17):

    [ 60%] Building CXX object dune/common/test/CMakeFiles/fvectorconversion1d.dir/fvectorconversion1d.cc.o
    /builds/core/dune-common/dune/common/test/fvectorconversion1d.cc:86:16: warning: unused variable 'mfv' [-Wunused-variable]
          MiddleFV mfv;
                   ^
    /builds/core/dune-common/dune/common/test/fvectorconversion1d.cc:107:16: warning: unused variable 'mfv' [-Wunused-variable]
          MiddleFV mfv;
                   ^
    2 warnings generated.

See also: [!735], [!562]

See merge request [core/dune-common!773]

  [https://gitlab.dune-project.org/core/dune-common/-/jobs/139437\#L665]: https://gitlab.dune-project.org/core/dune-common/-/jobs/139437#L665
  [!735]: gitlab.dune-project.org/NoneNone/merge_requests/735
  [!562]: gitlab.dune-project.org/NoneNone/merge_requests/562
  [core/dune-common!773]: gitlab.dune-project.org/core/dune-common/merge_requests/773

This is a regression test, the threw up undefined variable warnings.  unsure
about the correct fix, I tried to understand the test.  In addition to fixing
the warnings, I left some comments too, in the hope future readers will have a
little easier time understanding what it is supposed to do.

The warnings showed up in
https://gitlab.dune-project.org/core/dune-common/-/jobs/139437#L665 (debian:10
clang-7-libcpp-17):
```
[ 60%] Building CXX object dune/common/test/CMakeFiles/fvectorconversion1d.dir/fvectorconversion1d.cc.o
/builds/core/dune-common/dune/common/test/fvectorconversion1d.cc:86:16: warning: unused variable 'mfv' [-Wunused-variable]
      MiddleFV mfv;
               ^
/builds/core/dune-common/dune/common/test/fvectorconversion1d.cc:107:16: warning: unused variable 'mfv' [-Wunused-variable]
      MiddleFV mfv;
               ^
2 warnings generated.
```

See also: !735, !562

Merge branch 'update-compiler-requirements' into 'master'

ref:core/dune-common According to dev meeting 2020-02

See merge request [core/dune-common!772]

  [core/dune-common!772]: gitlab.dune-project.org/core/dune-common/merge_requests/772

According to dev meeting 2020-02

Merge branch 'function.hh-useful-deprecation' into 'master'

ref:core/dune-common Make the deprecation of function.hh more useful

-   Move it outside of inclusion guard so it triggers on every include (\#186)
-   #undef the disarming-define once it has suppressed a warning so the
    warning will fire again in the next include (\#186)
-   Mention the dune version in the warning so we know when we can finally
    remove it
-   deprecate also the individual classes and function in function.hh so it is
    easier to know what exactly to fix

See merge request [core/dune-common!769]

  [core/dune-common!769]: gitlab.dune-project.org/core/dune-common/merge_requests/769

Deprecate the classes and functions in function.hh too, so it is easier to
tell what one needs to do to update a file when it throws warnings

Make it possible to tell at a glance when the deprecation was put into effect,
so we can know when we can remove the stuff.

Clear the marker with which includers can suppress the deprecation warning
after skipping the warning.  This way, one suppressed warning will still allow
subsequent warnings to take effect.

Addresses: #186

Adresses: #186

Merge branch 'fix-function.hh-self-deprecation' into 'master'

ref:core/dune-common Don't emit the warning that function.hh is deprecated in
the test testing function.hh functionality.

See merge request [core/dune-common!768]

  [core/dune-common!768]: gitlab.dune-project.org/core/dune-common/merge_requests/768

Don't emit the warning that function.hh is deprecated in the test testing
function.hh functionality.

Merge branch 'deprecated-functionhh' into 'master'

ref:core/dune-common It contains the two base classes Function and
VirtualFunction. In downstream codes, these should be replaced by C++ function
objects, std::function etc.

Fixes [flyspray/FS#1677]

See merge request [core/dune-common!765]

  [flyspray/FS#1677]: flyspray/FS#1677
  [core/dune-common!765]: gitlab.dune-project.org/core/dune-common/merge_requests/765


Closes flyspray/FS#1677

It contains the two base classes `Function` and `VirtualFunction`.
In downstream codes, these should be replaced by C++ function objects,
`std::function` etc.

Merge branch 'feature/remove-deprecated-latex-support' into 'master'

See merge request [core/dune-common!763]

  [core/dune-common!763]: Nonecore/dune-common/merge_requests/763

Merge branch 'unimport-shared-ptr' into 'master'

ref:core/dune-common This is a left-over from the days where Dune had its own
implementation of std::shared_ptr. Now that that is long gone, it violates the
principle of least surprise to find shared_ptr in Dune::

See merge request [!764]

  [!764]: gitlab.dune-project.org/core/dune-common/merge_requests/764

This is a left-over from the days where Dune had its own
implementation of std::shared_ptr.  Now that that is long gone,
it violates the principle of least surprise to find shared_ptr
in Dune::

As a side effect, this patch removes most of the code from
sharedptrtest.cc.  As we don't have our own shared_ptr implementation
anymore, there is no more reason to test it.

Merge branch 'fix/matrix_constexpr_size' into 'master'

ref:core/dune-common This MR makes the default constructor of the FieldMatrix
and DiagonalMatrix classes constexpr and makes their size methods
`static constexpr` - just like it is already done in the FieldVector class.

Closes [#156].

See merge request [core/dune-common!641]

  [#156]: gitlab.dune-project.org/NoneNone/issues/156
  [core/dune-common!641]: gitlab.dune-project.org/core/dune-common/merge_requests/641


Closes #156

Felix Müller authored 5 years ago and Oliver Sander committed 5 years ago

N() and M() methods now work as constexpr for Field/DiagonalMatrx; Added tests for those constexpr calls

Merge branch 'feature/support-manually-set-ninja-in-fortran-test' into 'master'

ref:core/dune-common Prior to this change the build program (make, Ninja) was
not identical to the one used by CMake, but the one installed on the system.

I found this when testing Fortran support of upcoming CMake 3.17 with upcoming
Ninja 1.10 - which works!

See merge request [core/dune-common!761]

  [core/dune-common!761]: gitlab.dune-project.org/core/dune-common/merge_requests/761

Prior to this change the build program (make, Ninja) was
not identical to the one used by CMake, but the one
installed on the system.

Merge branch 'fix-python-venv-debian-testing' into 'master'

ref:core/dune-common cmake parameters are passed as a list. The "-p
${PYTHON_EXECUTABLE}" option was passed as string, which lead to problems
setting up the venv on my Debian testing system.

We now pass all parameters as lists, just like it should be\...

1.  @core: perhaps someone from the cmake and/or python crowd should have a
    look\...
2.  I guess this wuld be god in 2.7?!

See merge request [core/dune-common!747]

  [core/dune-common!747]: gitlab.dune-project.org/core/dune-common/merge_requests/747

Merge branch 'add_missing_install_header' into 'master'

See merge request [core/dune-common!754]

  [core/dune-common!754]: Nonecore/dune-common/merge_requests/754

Merge branch 'issue/add_missing_install_file_quadmath' into 'master'

ref:core/dune-common Maybe this MR could also be cherry-picked into the
releases/2.7 branch

See merge request [core/dune-common!759]

  [core/dune-common!759]: gitlab.dune-project.org/core/dune-common/merge_requests/759

Merge branch 'gcc10' into 'master'

See merge request [core/dune-common!758]

  [core/dune-common!758]: Nonecore/dune-common/merge_requests/758

GCC 10's libstdc++ deleted some `operator<<` overloads to write wide
characters to non-wide streams as these would be treated as integers
instead of characters. One could use wide variants `wstringstream`,
`wstring` instead of the usual `stringstream`, `string`, but at some
places would have to convert between different character
representations.

As wide characters really should only be used for text, DUNE doesn't
really need to support them as numerical types here. So we just drop
the tests using wide character types.

This addresses compiler errors like
```
../dune/common/simd/test.hh:1732:20: error: use of deleted function ‘std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, wchar_t) [with _Traits = std::char_traits<char>]’
In file included from /usr/include/c++/10/iostream:39,
                 from ../dune/common/simd/test.hh:12,
                 from dune/common/simd/test/standardtest_vector_wchar_t.cc:5:
/usr/include/c++/10/ostream:538:5: note: declared here
  538 |     operator<<(basic_ostream<char, _Traits>&, wchar_t) = delete;
```

Several members of `std::allocator` were already deprecated in C++17
and have now been removed in C++20. This patch uses the appropriate
members of `std::allocator_traits` instead.

Merge branch 'fix/issue-183-skipped-tests' into 'master'

ref:core/dune-common Fixes [#183].

See merge request [core/dune-common!755]

  [#183]: gitlab.dune-project.org/NoneNone/issues/183
  [core/dune-common!755]: gitlab.dune-project.org/core/dune-common/merge_requests/755


Closes #183

This fixes the bug (#183) introduced with a225b2da.
The command can be a complex path while for skipped tests
we actually want the test command to just be equal to
the target name (executable). This name is
expanded to a full path using the TARGET_FILE generator
expression so it should work on all platforms that CMake
supports.

Merge branch 'fix/install-latex-doc-optional' into 'master'

ref:core/dune-common Otherwise target "install" fails when target "doc" was
not run.

Fixes [#182]

See merge request [core/dune-common!751]

  [#182]: gitlab.dune-project.org/NoneNone/issues/182
  [core/dune-common!751]: gitlab.dune-project.org/core/dune-common/merge_requests/751


Closes #182

Otherwise target "install" fails when target "doc" was
not run.

Merge branch 'bugfix/headercheck-mpifuture-mpipack' into 'master'

ref:core/dune-common mpifuture.hh and mpipack.hh missed includes for
Communication.

See merge request [core/dune-common!752]

  [core/dune-common!752]: gitlab.dune-project.org/core/dune-common/merge_requests/752