In Visual Studio 2015 Solution Explorer next to C++ files is a "++" icon, easy enough to understand, but I have one C++ file that has a red circle with a white minus sign in it over the "++" icon. I have tried making changes to this file and checking it into TFS, the icon does not change.
Short questions: What does a red circle with a white minus sign in it over the "++" icon mean??
Bonus question: I searched all over trying to get a list of the icons, without any success, does a list of these icons exist??
07.Nov.2016 Update: This question was asked and answered in 2012, but I feel this posting should remain, because both the question and answer include screen shots. A picture is worth a least a 1,000 words!