Quick Q: How to accept lambdas as callbacks? -- StackOverflow
The poster is definitely thinking along the right lines -- anything callable that would have accepted a pointer to function and/or functor in C++98 should be written to be able to accept a lambda function in modern C++.
So what about callbacks as a specific example?
Passing and storing lambda function as callbacks
I was wondering if this would be an accepted approach to writing callbacks:
Storing callbacks:
struct EventHolder { std::function<void()> Callback; EventTypes::EventType Type; }; std::vector<Events::EventHolder> EventCallbacks;Method definition:
void On(EventType OnEventType,std::function<void()>&& Callback) { Events::EventHolder NewEvent; NewEvent.Callback=std::move(Callback); NewEvent.Type=OnEventType; EventCallbacks.push_back(std::move(NewEvent)); }Binding event:
Button->On(EventType::Click,[]{ // ... callback body });My biggest question would be regarding passing the Callback by value. Is this a valid approach?
[Ed.: We're calling particular attention to this paper as of broad interest to the community, although still undergoing standardization. This is one of the major papers being considered at the upcoming Bristol standards meeting in April for near-term standardization work.]
