Right now, when we use optional, we take it from boost.
We want to move to std::optional when available (based on BOOST_NO_CXX17_HDR_OPTIONAL), unless the user explicitly choose not to by setting BOOST_MPI_FORCE_BOOST_OPTIONAL in boost/mpi/config.hpp
Right now, when we use optional, we take it from boost.
We want to move to std::optional when available (based on BOOST_NO_CXX17_HDR_OPTIONAL), unless the user explicitly choose not to by setting BOOST_MPI_FORCE_BOOST_OPTIONAL in
boost/mpi/config.hpp