"Now we go into new territory. Open the file Tutorial_9Main.h (Use File | Open … to do so.) and add printg to its public members as shown here."
where are the example files he refers to??
You need to do exactly the steps as written there. This:
Open Code::Blocks and create a new project called Tutorial_9. We want a form that looks like the one shown below.
...will create a new project, including these files.