Comment by Joky

I don't get it, they are interested in closure and have a codebase in C, why not simply using C++11 with lambda? This would make the code portable to GCC/MSVC... Arguably they started before C++11 was officially released, but clang and gcc supported lambda before the official release, and also since then they could have used a rewriter to transform their blocks into lambda to help for the conversion.