Fix GeometryGrid's fake iterators

The fake iterators provided by GeometryGrid were buggy. Code using them would fail to build.

Why is the test you wrote GeometryGrid-only? Doesn't it test something that should hold for all grids, and therefore be integrated into the main test?

@oliver.sander I think this is already checked in the grid check, however GeometryGrid only uses YaspGrid as the host grid. So the fake iterators are not tested. I guess a better solution might be to use UGGrid as a second host grid for the tests. I'll have a look if this also triggers the problem.

I also noticed that my code now compiles, but there seem to be further bugs. So I'll set this merge request to WIP for now.

Marked this merge request as a Work In Progress

Building test-geogrid also with UGGrid as the host grid works with a few more patches, however:

% ./dune/grid/test/test-geogrid-uggrid 2>&1 | grep -c Error:
1944

Interestingly the test still returns 0 (success)...

mentioned in issue #12

Added 12 commits:

• 8458d064...b88410cd - 3 commits from branch master
• 1384fec0 - Typo: defualt -> default
• 2ccf5e84 - EntityBase (fake): add missing constructor
• 5a4baaa9 - Pass correct template argument
• c3228003 - Use correct host iterators
• 8399aed1 - Do not dereference entities
• eae5f4ff - vertexPartitionType: return type of ith vertex
• 11f80614 - Also copy grid_ member variable
• a0284945 - Also test GeometryGrid with UGGrid as host grid
• b4d36b28 - Reorder initializer lists

I replaced the new test by building a second version of test-geogrid.cc with UGGrid as the backend. This showed a few more bugs that had to be addressed, but the grid check now passes.

Unmarked this merge request as a Work In Progress

Is there still anything to be done before this can be merged?

mentioned in commit 4baece1f

Status changed to merged

This leads to a test failure for me. Is that known? Here's what I get:

[ 75%] Building CXX object dune/grid/test/CMakeFiles/test-geogrid-uggrid.dir/test-geogrid.cc.o
In file included from /home/mi/pipping/dune/dune-grid/dune/grid/test/test-geogrid.cc:21:
In file included from /home/mi/pipping/dune/dune-grid/dune/grid/geometrygrid.hh:3:
In file included from /home/mi/pipping/dune/dune-grid/dune/grid/geometrygrid/grid.hh:12:
In file included from /home/mi/pipping/dune/dune-grid/dune/grid/geometrygrid/datahandle.hh:11:
/home/mi/pipping/dune/dune-grid/dune/grid/geometrygrid/entity.hh:578:9: error: value of
      type 'const Dune::GeoGrid::EntityBase<1, const Dune::GeometryGrid<Dune::UGGrid<2>,
      Dune::IdenticalCoordFunction<double, 2>, std::allocator<void> >, true>' is not
      contextually convertible to 'bool'
        assert( *this );
        ^~~~~~~~~~~~~~~

Argh, assert in tests :( No, I didn't notice this as I ran the testsuite with my usual compiler options which include -DNDEBUG. I'll try to take a look at this tomorrow.

Mentioned in commit 4baece1f