I am using boost::signals2::signals
in a component, UpdateComponent
. A specific aggregate for this component is of type Updateable
. I would like Updateable
to be able to connect to UpdateComponent
's boost::signals2::signal
. I should note that the Updateable
's slot
is pure-virtual
.
Below is a concrete example of the code:
// This is the component that emits a boost::signals2::signal.
class UpdateComponent {
public:
UpdateComponent();
boost::signals2::signal<void (float)> onUpdate; // boost::signals2::signal
}
At some point in UpdateComponent
's code, I perform onUpdate(myFloat)
; I believe this is akin to "firing" the boost::signals2::signal
to all of its "listeners".
// The is the aggregate that should listen to UpdateComponent's boost::signals2::signal
class Updateable {
public:
Updateable();
protected:
virtual void onUpdate(float deltaTime) = 0; // This is the pure-virtual slot that listens to UpdateComponent.
UpdateComponent* m_updateComponent;
}
In Updateable
's constructor, I do the following:
Updateable::Updateable {
m_updateComponent = new UpdateComponent();
m_updateComponent->onUpdate.connect(&onUpdate);
}
I receive the following two errors:
...Updateable.cpp:8: error: ISO C++ forbids taking the address of an unqualified or parenthesized non-static member function to form a pointer to member function. Say '&BalaurEngine::Traits::Updateable::onUpdate' [-fpermissive]
/usr/include/boost/function/function_template.hpp:225: error: no match for call to '(boost::_mfi::mf1<void, BalaurEngine::Traits::Updateable, float>) (float&)'
I should mention I am using Qt in conjunction with boost. However, I have added CONFIG += no_keywords
to my .pro
file, so the two should be work together smoothly, as outlined on the boost website. The reason I don't use Qt's signals
and slots
(which works very well) is: I do not want Updateable
to be a QObject
.
If someone could help me figure out why I am getting an error, it would be greatly appreciated!
The slot you are passing to connect
must be a functor. To connect to a member function, you can use either boost::bind
or C++11 lambda
. For example using lambda:
Updateable::Updateable {
m_updateComponent = new UpdateComponent();
m_updateComponent->onUpdate.connect(
[=](float deltaTime){ onUpdate(deltaTime); });
}
or using bind
:
Updateable::Updateable {
m_updateComponent = new UpdateComponent();
m_updateComponent->onUpdate.connect(
boost::bind(&Updateable::onUpdate, this, _1));
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.