what do these Project Explorer icons mean?

Hi Leo,

The icons seen when you expand a C header file simply designate whether an object, or line of code, is a variable or a function. The first icon shown in the image you attached designates a defined variable. The second designates that the line to the right is a function. When an icon has a line through it, such as those at the bottom of the image, it just means that those lines are not defined at the moment, but are still in the code.

Hope this helps! If you have any confusion on what some of the other symbols mean, simply double click the variable/function and look at what the return value is. It should be pretty self-explanatory from there.

Regards,
Michael Arriete