Qt-style Signal/Slot

1#include <functional>
2#include <vector>
3#include <string>
4 
5class Object {
6public:
7  virtual ~Object() = default;
8};
9 
10template<typename... Args>
11class Signal {
12  std::vector<std::function<void(Args...)>> slots_;
13 
14public:
15  void connect(std::function<void(Args...)> slot) {
16    slots_.push_back(slot);
17  }
18 
19  void emit(Args... args) {
20    for (auto& slot : slots_) {
21      slot(args...);
22    }
23  }
24};
25 
26class Button : public Object {
27public:
28  Signal<> clicked;
29  Signal<int, int> moved;
30 
31  void click() {
32    clicked.emit();
33  }
34 
35  void move(int x, int y) {
36    moved.emit(x, y);
37  }
38};
39 
40class Label : public Object {
41  std::string text_;
42 
43public:
44  void setText(const std::string& text) {
45    text_ = text;
46  }
47 
48  void onButtonClicked() {
49    setText("Clicked!");
50  }
51};