DUNE usage of std::optional incompatible to Apple Clang
dune-funcions and downstream modules won't compile with Apple Clang v10.
Included warning in
README.md: !113 (merged).
Apple Clang v10 introduces an implementation for
std::optional. DUNE uses its own fall-back implementation in dune-common if the compiler does not support this feature. This was the case until now for Apple Clang. Now the compiler ships with its own implementation, but it is incompatible to the usage of
std::optional<Geometry> in dune-functions.
Steps to reproduce
Try to compile DORiE and its DUNE dependencies with Apple Clang 10.
What is the current bug behaviour?
dune-functions, dune-pdelab, and DORiE won't build.
What is the expected correct behaviour?
Build log for dune-functions: log.txt
This issue has been reported to DUNE at
Ideas how to fix this?
Use CMake flag
-DDUNE_HAVE_CXX_OPTIONAL=OFF to disable the check for
std::optional for now.