Question

I have another one question about functions reference.
For example, I have such definition:

typedef boost::function<bool (Entity &handle)> behaviorRef;
std::map< std::string, ptr_vector<behaviorRef> > eventAssociation;

The first question is: how to insert values into such map object?

I tried:

eventAssociation.insert(std::pair< std::string, ptr_vector<behaviorRef> >(eventType, ptr_vector<behaviorRef>(callback)));

But the error:

no matching function for call to ‘boost::ptr_vector<boost::function<bool(Entity&)> >::push_back(Entity::behaviorRef&)’

And I undersatnd it, but can’t make workable code.

The second question is how to call such functions?
For example, I have one object of behaviorRef, how to call it with boost::bind with passing my own values?

Answer 1

PART 1

There’s no need to use a ptr_vector. boost::function has value semantics, so can be stored in a standard container. So the following should work:

typedef boost::function<bool (Entity &handle)> behaviorRef;
std::map< std::string, std::vector<behaviorRef> > eventAssociation;

eventAssociation.insert(std::make_pair(eventType, vector<behaviorRef>(1, callback)));

Note the two arguments to the vector constructor.

If you did need a ptr_vector (because you were using a noncopyable type), you’d need something like the following, since ptr_vector doesn’t have a constructor that populates the vector:

ptr_vector<behaviorRef> behaviours;
behaviours.push_back(new behaviourRef(callback));
eventAssociation.insert(std::make_pair(eventType, behaviours));

PART 2

There’s no need to use boost::bind for calling the function (although you can use it to make it in the first place). The syntax for calling it is the same as for a normal function:

behaviourRef behaviour;
Entity entity;
bool result = behaviour(entity);