Files are edited in the C/C++ editor that is, by default, located in the editor area to the right of the C/C++ Projects view.
The marker bar on the left margin of the C/C++ editor, displays icons for errors, warnings, bookmarks, breakpoints and tasks.
For more information on the marker bar, see Workbench User Guide > Reference > User interface information > Views and editors > Editor area.
To create a C++ file:
The file will open in the C/C++ editor.
CDT Projects
Project file views
Displaying C/C++ file components in
the C/C++ Projects view
Hiding files by type in the C/C++
Projects view