[boost] Required C++ version in meta/libraries.json

Hi, How can I specify required version of the standard in the library meta info? Where is documentation of libraries.json schema? I've learned that "std":"C++17", for example, in Boost.Any states which standard adopted the library. That is not what I'm after. -- Mateusz Loskot, mateusz@loskot.net (Sent from mobile, may suffer from top-posting)