Hi, I want to start a new sub-thread about some of the concerns of Steven Watanabe about whether some of the contents of this library fits better in Boost.Config. In particular the file boost/fit/returns.hpp. Others could be considered also as function.hpp, lambda.hpp and lift.hpp, as the macros are there to workaround some missing language features, but those are much more specialized (Boost.Core?) John M., Peter D. what do you think? Steven, were you thinking on other parts of the library? Paul, it is normal that you added those utilities in your library, as Boost doesn't provides them, however them can be included as sub-modules of other libraries. Best, Vicente returns doc http://pfultz2.github.io/Fit/doc/html/returns/index.html file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/returns.hpp function doc http://pfultz2.github.io/Fit/doc/html/function/index.html file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/function.hpp lambda doc http://pfultz2.github.io/Fit/doc/html/lambda/index.html file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/lambda.hpp lift http://pfultz2.github.io/Fit/doc/html/lift/index.html file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/lift.hpp