Improve specializations of Hybrid::size()

See merge request !1209

Carsten Gräser authored 2 years ago and Simon Praetorius committed 2 years ago

The interfaces tested subsequently for `Hybrid::size(const T& t)` are now

* standard tuple-like interface `std::tuple_size<T>::value` (e.g. needed for `std::tuple`),
* static constexpr `T::size()` (e.g. needed for `Dune::TupleVector`),
* dynamic member function `t.size()` (e.g. needed for `std::vector`).

This patch removes a special case for `FieldVector` which is already covered
by the `static constexpr size()` case. To ensure this, a corresponding test
case was added. Also the documentation of the different cases was fixed.

Notice that this does not work necessarily with matrices, because many of them
only provide a (potentially `static constexpr`) method `N()` instead of `size()`.

Add utility IsCompileTimeConstant and use it in HybridFunctor

See merge request !1226

Revert "Merge branch 'feature/py-improve-parallel-communication-interface' into 'master'"

See merge request !1235

This reverts merge request !1230

[python,parallel] improve compatibility of Dune::Communication<...> and mpi4py

See merge request !1230

Make Field(Matrix|Vector) constructor from initializer_list constexpr

See merge request !1234

This allos to do

```cpp
constxpr M = Dune::FieldMatrix<double,2,2>{ {1,2}, {3,4}};
```

Notive that `copy_n` is not `constexpr`. Hence we implement this
with a manual for loop.

Fix/python bindings python requirements

Closes #297

See merge request !1096

and not the other way around (set the variable only if the checks passed)

Markus Blatt authored 3 years ago and Timo Koch committed 2 years ago

If there is no python interpreter then it will do nothing.

[python][test] Use python3 in dune_python_add_test

See merge request !1223

[feature][Python] Make use of venv optional. Default is ON.

See merge request !1222

Timo Koch authored 2 years ago and Robert K committed 2 years ago

[python][cmake] For DUNE_PYTHON_USE_VENV=FALSE exit FATAL_ERROR if attempt to call dune_python_configure_dependencies

off.

Timo Koch authored 2 years ago and Robert K committed 2 years ago

This checks that the external venv has the matching dune packages
installed. The user needs to take care of that because they actively
disabled the Dune-provided venv automatism.

Make Hybrid::switchCases more hybrid

See merge request !1231

- add MPI_Comm wrapper
- add conversion from mpi4py.MPI.Comm to MPI_Comm wrapper
- allow to construct dune.common.Communication from mpi4py.MPI.Comm