GridFormat v0.3.0

Features

• Writers: the custom range adaptors & iterators used by the writers under the hood have been changed to support range sentinels of different type than the range iterator. This makes it easier to specialize the traits for grid implementations that use sentinels of different type than the grid entity iterators.
• Traits: support for writing Dune::FieldMatrix as tensor field data.
• Reader: the Reader class now allows for opening a file upon instantiation using GridFormat::Reader::from(filename) (taking further optional constructor arguments). Moreover, you can now open a file and receive the modified reader as return value using reader.with_opened(filename).
• VTK: VTK-XML files of the older file format version 0.1 can now also be read by all vtk readers

Deprecated interfaces

• Common:
  • the get_md_layout<SubRange>(std::size_t) overload is deprecated as it may interfere with get_md_layout<Range>(Range) if Range is constructible from an std::size_t and the template argument Range is explicitly specified. The intented behaviour can now be achieved with MDLayout{{std::size_t}}.with_sub_layout_from<SubRange>().
  • related to the above, an MDLayout for a scalar value now has a dimension of zero to distinguish it from a vector of size 1.

Continuous integration

• on PRs, a bunch of performance benchmarks are run with the code of the PR and the target branch, and observed runtime differences are posted as a comment to the pull request.
• the CI helper scripts, for instance, to select tests affected by changes, have been moved from the /bin to the /test directory.
• the runtime of the test pipeline has been reduced by avoiding duplicate test runs and skipping those tests in pull requests for which no changes are introduced.
• the CI now runs on ubuntu:24.04 and tests the code with gcc-14 and clang-18.