OptiX sdk sample projects missing optixu_device.h included

Hi all,
I use cmake to compile the sdk sample projects, and use visual studio 2017 to open it up, I double check all the CUDA and OptiX include files and library are correctly setup up, but something like RT_Program, rtDeclareVariable are missing and show up errors in visual studio, after checking header files, I include another file optixu_device.h and all the errors are gone, I wonder if something is wrong from my side or the sample codes are from older version of SDKs, if that is my fault, besides include, libs, anything else I should include or add to my vs project setting to kill all the errors?

Many thank.