>I managed to write the whole library without a single #ifdef! Generates Linux .so, OS X .dylib, and Windows DLLs. Amazing!

Could you expand on how you are doing this? You're still using a Makefile or a similar tool with some kind of platform detection for the build itself, right?

Not sure whether the parent does it like this, but you can use cmake to describe the build, and then (for instance) run cmake --build to build the project in a 'cross-platform' way using the platform's native compiler toolchain, it works the same on Windows, OSX and Linux. I think what the parent meant with 'no #ifdefs' is that the C++11 std lib comes with more modules that make a lot of platform-specific code-paths unnecessary (for instance std::thread, std::atomic for threading, and std::chrono for high-resolution time-measuring).

Yup, you nailed it. cmake for handling the builds, and the C++11 stdlib covers every platform-specific thing I needed. The only platform-specific thing I needed to do was point the CMakeLists.txt at the correct libusb (libusb.so, libusb.dylib, libusb.dll). Absolutely beautiful.

Edit: to elaborate a little more about cmake... You can use cmake to generate both Makefiles and Visual Studio build files.

On Windows:

mkdir build; cd build; cmake .. -G "Visual Studio 12 2013"; cmake --build .

On OS X or Linux:

mkdir build; cd build; cmake ..; make