The Signal Network library was built with push-based networks in mind (the data producer sends data through a signal), but it can also be used for pull-based networks (the data consumer requests data through a signal).

The following example illustrates this:

signals::storage<void(float), signals::unfused> generator(1.0f);
PullDoubler doubler;
    
doubler >>= generator.value_at_slot<0>();
    
BOOST_CHECK(doubler() == 2.0f);

The example uses the following classes:

class PullDoubler : public signals::filter<float (), signals::unfused>
{
public:
    float operator()()
    {
        return 2*out();
    }
};