In IB API 9.69, the C++ sample doesn't provide a ready-to-go project. Anyone is using 9.69? How did you make it work?
TWS API 9.69 has both Posix C++ sample (cross platform) and Visual C++ (MFC based project). Starting with 9.69 there is new type of installation procedure that extracts files to TWS API folder with three sub-folders bin, samples and source. In samples folder look at TestActiveX_VC folder for MFC or in source folder check CppClient folder. IB manual describes what folders should be included for C++ build. I was testing Posix API on Windows only and it worked after few modifications in Visual Studio. IB manual shows you how to build it using makefiles. Make sure that you download latest version of 9.69 from their site because the first one did not build all samples (specifically ActiveX) correctly.