C++Builder supports Boost, a common and useful C++ library. Through the GetIt package manager, you can install a build of v1.55 for our Clang compilers, or if you are using the classic compiler, an older version of Boost, v1.39.
The version available on GetIt for 10.2 had an issue for non-header-only Boost libraries. Most of Boost is available through headers, but some libraries, like system and filesystem, require .cpp files and so build and are linked against our RTL. The download linked these against the 10.1 version of our RTL. It is always a bad idea to try to link files built with two different versions against each other (never do this!) and we've made significant improvements in our RTL since 10.1 in some low-level areas and this meant the files would not link at all.
We have an updated build of Boost available now.