Replace DUNE_UNUSED by [[maybe_unused]]

See merge request !20

* adapt to changes in dune-common
* fix deprecation warnings

Introduce empty changelog

See merge request !19

Modernize CI script

See merge request !17

Replace deprecated getRealImplementation by impl()

See merge request !13

This fixes a few compiler warnings in the tests.

Feature/fix deprecation warnings

See merge request !16

Update CI config to clang-7

See merge request !15

The old image is no longer updated

Remove std::variant fallback

See merge request !14

The implementation is now part of dune-common and maintained there.

Fix/compatibility with mac

See merge request !11

* <tr1/memory> is not available on Mac

* uint is not available on Mac

fix -Winjected-class-name warnings in Clang

See merge request !10

When compiling with Clang 5.0.1 one gets two warnings about nested type
specifiers that were probably not intended to be there in the first
place. The first one is asking a *_t type trait for ::type and the
second one is asking for Entity::Entity.

The exact warnings given by Clang were:

/duneci/modules/dune-subgrid/dune/subgrid/common/variant.hh:31:66: warning: ISO C++ specifies that qualified reference to 'type' is a constructor name rather than a type in this context, despite preceding 'typename' keyword [-Winjected-class-name]
    using Storage = typename std::aligned_storage_t<sizeof(Tp)>::type;
                                                                 ^

/duneci/modules/dune-subgrid/dune/subgrid/subgrid.hh:1190:67: warning: ISO C++ specifies that qualified reference to 'Entity' is a constructor name rather than a type in this context, despite preceding 'typename' keyword [-Winjected-class-name]
            typedef typename HostGrid::template Codim<0>::Entity::Entity HostGridElement;
                                                                  ^

Signed-off-by: Jonathan Youett <youett@math.fu-berlin.de>

Fix variant fallback

See merge request !7

If the variant object was destroyed, the memory for the object itself was properly
free'd. However, the dtor would never been called on the object (unless it's of literal type)
and hence memory that was itself managed by the object would leak. The same reasoning
applies if the type of the object held by the variant changed. This commit fixes this and cleans up
when appropiate.

O/w certain types (for instance FieldVectors) could not be stored.

Implementations for geometryInInside() and geometryInOutside()

See merge request !5

This is a fallback implementation of C++17's std::variant. It does not model the complete
STL interface but the basis functionality is there. There are probably many corner cases this
implementation can not handle yet.
This should probably be in dune-common, but for now, I'll put it here.

Cleanup/indexstorage

See merge request !6