thank you for your post.
The error you are seeing might be because you are not passing compile flag
FL_CPP11. In your project, I think you need to add the preprocessor definition
I have worked only on making sure everything runs fine in MSVC (2010-2015, [32|64]bit) and Unix (Mac OSX|ubuntu, [32|64]bit, clang|g++). I never managed (or tried hard) to get mingw running on my virtual box, and hence I do not know how or what fuzzylite needs in order to compile in mingw. Regardless, I reckon it is better to use MSVC than mingw because with mingw you would need to link to some additional libraries (or at least that is what I recall from a few years ago).
Anyway, if you make it run on mingw, it would be great if you let me know the necessary steps to have it compile there.