return value in action server

edit

There's a short snippet sn section 5 of the page you linked:

# Define the goal
uint32 dishwasher_id  # Specify which dishwasher we want to use
---
# Define the result
uint32 total_dishes_cleaned
---
# Define a feedback message
float32 percent_complete

See the line with # Define the result? The return type of this action is uint32 and the name of the return value is total_dishes_cleaned.

To set this return value have a look at the setSucceeded() signature found here:

void actionlib::SimpleActionServer< ActionSpec >::setSucceeded(const Result &   result = Result(),
    const std::string &     
    text = std::string("") 
)

You can call setSucceeded() with a result as parameter. In this result object you can set the return members.

In Python it works the same.