They can't compile the new constexpr decomposer because
`ITransientExpression` has a defaulted virtual destructor. We could
instead drop the virtual destructor - it only exists to silence
static analysis tools complaining about having virtual functions
without virtual destructor - but GCC 5 and 6 are positively ancient,
so we drop them instead.
The base images for GitHub Actions are updated weekly, but
sometimes that is not enough to be able to install the packages
we require. The recommended fix for this is to always run
`apt-get update` before `apt-get install`.
For now I added only the basic build matrix, without coverage
collection and more special builds, like WMAIN.
However, due to GHA being so much faster than AppVeyor, all
these builds are now done against the 'all-tests' prefix, making
the builds more uniform than they were on AppVeyor.
The Meson[1] build system makes it easier incorporate third-party
libaries into a project if they also build using Meson.
Let's add a minimal Meson build that's compatible with the CMake build,
along with a GitHub workflow to check that it builds and that at least
the simplest SelfTest runs.
The handling of catch_user_config.hpp is inspired by BUILD.bazel and
doesn't attempt to support any configuratons options. Such features
could be added later.
Meson strongly discourages using wildcards to specify sources, so the
source and header lists are copied from CMakeLists.txt.
Add a new test workflow to test the Meson builds. I was unable to get
these tests to pass with Ubuntu 20.04, so they use Ubuntu 22.04.
I'm neither a CMake nor a Meson expert, but the results seem to work for
me.
[1] https://mesonbuild.com/
Co-authored-by: Mike Crowe <mcrowe@brightsign.biz>
* Fixed problem with older compilers by explicitly installing the
right compiler version.
* Split apart simple builds that can be well described by a build
matrix, and builds that need special CMake defines or similar
special snowflake handling.
* Ported some extras + examples builds from TravisCI to GitHub
Actions.
