For a long time now we have keep the core of midas (odb.c, midas.c, etc) compatible with plain C and by default 
we have built the MIDAS library using the plain C compiler. Over time, we have switched most MIDAS programs 
(mhttpd, mlogger, mdump, odbedit, etc) to C++ (with happy results). (and for a long time now, all of MIDAS 
could be build as C++, even if the default build remained plain C).

The main reason for keeping the core of MIDAS as C has been to allow writing MIDAS frontends in C - for 
example, in environments with no C++ compilers or no C++ runtime (VxWorks) or where C++ had too much 
overhead (small memory machines, etc).

Today, all concerns against using C++ seem to have receded into the past. C++ compilers are now always 
available, even for small embedded systems. C++ overheads are now well understood and one can easily write 
C++ code that is as efficient as C for using limited CPU and memory resources. (While at the same time, today's 
embedded systems tend to have more CPU and RAM than "big" MIDAS DAQ machines had in the past - 1GHz 
CPU, 1GB RAM is pretty typical for embedded ARM).

As examples of small hardware where MIDAS frontends written in C++ worked just fine, consider the T2K ND280 
FGD data collector running on XILINX FPGA with a 300MHz PowerPC and 128 Mbytes of RAM (standard Linux 
kernel) and the GRIFFIN Clock distribution module control running on a Microsemi FPGA with a 300MHz ARM 
CPU (ucLinux without an MMU). More typical Cyclone-5 ARM SoCs with 1GB RAM and 1GHz CPU run standard 
Linux (CentOS7) and can build MIDAS natively (no need for cross-compiling).

With the removal of the requirement to make it possible to write MIDAS frontends in C, we can switch the MIDAS 
default build to C++ and start using C++ features in the MIDAS API (std::string, std::vector, etc).

Next to consider is "which C++ should we use?".

K.O.