Hi all, the recent activity regarding adding CMake support to some remaining libraries (many thanks go to Peter Dimov), encouraged me to try using FetchContent to integrate Boost into client projects. I'm sure many people are interested in such a possibility in order to reduce dependencies on the build environment. The brief result seems to be: It almost works. Enough to make it interesting. The reason for my message is to ask if this is supposed to work, i.e. if I am trying something that should work, either now or in the near future, or if it is a frivolous expectation on my part. A toy project's CMakeLists.txt might look like this: ============================================================= cmake_minimum_required(VERSION 3.21) project(boost_test) include(FetchContent) set(BOOST_ENABLE_CMAKE ON) FetchContent_Declare(build_boost GIT_REPOSITORY https://github.com/boostorg/boost.git GIT_TAG boost-1.77.0.beta1 ) FetchContent_GetProperties(build_boost) if(NOT build_boost_POPULATED) FetchContent_Populate(build_boost) add_subdirectory( ${build_boost_SOURCE_DIR} ${build_boost_BINARY_DIR} EXCLUDE_FROM_ALL ) endif() add_executable(boost_test boost_test.cpp) target_link_libraries(boost_test PRIVATE Boost::format) ============================================================= The corresponding source file would look like this: ============================================================= #include <boost/format.hpp> #include <iostream> int main() { std::cout << boost::format("Hello %1%!") % "everybody"; } ============================================================= I used the CMake GUI version 3.21.0 on Windows 10 to configure the project for Visual Studio 2019 Release 16.10.3 with a 64-bit build. It produced lots of install-related errors in the generation phase, but it nevertheless pruduced a solution that successfully built the project. Now, there are of course a couple of issues, which I'd like to get your opinion on: 1. Optimized source download As listed, FetchContent pulls in the entire boost sources, regardless whether they're needed or not. This takes a significant amount of time and uses a lot of disk space for no benefit. Clearly, you would want to fetch only the sources you need, but there doesn't seem to be a good way to handle the dependencies between the various boost libraries. You could use the GIT_SUBMODULES option of FetchContent, but you'd need to list not only the libraries you directly use (Boost::format in my example above), but you also need to list the dependencies of those, which is tedious and brittle. I imagine that this can be handled via a special tool that gets invoked as a PATCH_COMMAND, which is able to scan through the submodules that have been populated and populates all its dependencies. I haven't seen such a tool anywhere, but maybe somebody has got a solution already? 2. Dealing with install Obviously, when using Boost like this, I don't want it to add installation items into the install of my own project, therefore I used the option EXCLUDE_FROM_ALL of add_subdirectory(). That doesn't eliminate all of the problems, as is evidenced by the myriad install-related errors that CMake flags up. Do you have an idea how to properly deal with that? I'm slightly out of my depth here. If you want to check this on your system, the CMake errors may prevent building. I have been able to build when generating a Visual Studio solution, but not when I openend the folder in Visual Studio directly, relying on Visual Studio's own CMake support. Of couse, if you have other suggestions, please tell! Cheers Stefan Heinzmann