Q>Может, memory-mapped files?

Q>[1] Memory-mapped files: https://docs.microsoft.com/en-us/dotnet/standard/io/memory-mapped-files
Q>[2] MemoryMappedFile Class: https://docs.microsoft.com/en-us/dotnet/api/system.io.memorymappedfiles.memorymappedfile?view=net-5.0

Может, похоже MemoryMappedFile работают через WinApi.
А boost::interprocess::mapped_region тоже интересно через WinApi?
Похоже что может по-разному
https://www.boost.org/doc/libs/1_46_0/boost/interprocess/mapped_region.hpp

#if (defined BOOST_INTERPROCESS_WINDOWS)
#  include <boost/interprocess/detail/win32_api.hpp>
#else
#  ifdef BOOST_HAS_UNISTD_H
#    include <fcntl.h>
#    include <sys/mman.h>     //mmap
#    include <unistd.h>
#    include <sys/stat.h>
#    include <sys/types.h>
#    if defined(BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS)
#      include <sys/shm.h>      //System V shared memory...
#    endif
#    include <boost/assert.hpp>
#  else
#    error Unknown platform
#  endif

#endif   //#if (defined BOOST_INTERPROCESS_WINDOWS)