//Configure VS2015/VS2015/VS2015/VS2015/VS2015/VS2015/VS2015

The CXX compiler identification is unknown

Cmake can’t find the C++ compiler. Check the VS installation directory for cl.exe, rc.exe and rcdll. DLL.
If you do not have cl.exe, you may have only installed VS and no VC compiler. Open VS and select VC to install.
If you do not have rc.exe and rcdll. DLL, which are used for compiling resources, you may install them in the Windows SDK. You can directly copy these two files to the VC/bin directory.