This library is something between redis and sqlite. I needed portable database for my desktop app and sqlite is a great solution of this problem, but I didnt need all that power and might of SQL. All i needed was hashes, strings and numbers. So actually it should be something like redis, but portable.
Building.
Linux:
Move to oodb and execute "CXX=clang++ make .". The result would be a static library. Make sure you've got libc++ (by LLVM) installed. Problem using gcc and libstdc++ is absence of std::regex support.
Windows:
Just use cmake to generate solution and build it.
MacOS:
It also compiles on MacOS using clang.