Visual Studio does not underline error (cend is not a member of...)

Question

I downloaded these 2 codes from GitHub because I want to edit them without having to recompile Point Cloud Library. I have edited the relevant includes so that the new hpp files links to the new h file.

https://github.com/PointCloudLibrary/pcl/blob/master/segmentation/include/pcl/segmentation/supervoxel_clustering.h https://github.com/PointCloudLibrary/pcl/blob/master/segmentation/include/pcl/segmentation/impl/supervoxel_clustering.hpp

However, I get an error as shown below. It says cend is not a member of a certain class. My question is, why doesn't visual studio underline the errors I get ?