我正在开发一个类来管理一些回调,例如鼠标点击或显示(当窗口需要刷新时调用回调)
回调和句柄保存在地图中。我试图创建一个可以在地图中注册回调的函数(addCallback)。
class CallBackManager {
public:
enum CallBackType {
DISPLAY = 1 << 0,
MOUSE = 1 << 1
};
template<typename T>
void AddCallback(CallBackType type, int hwnd, T f) {
if (type & DISPLAY) {
addDisplayCallback(hwnd, f); // 50 lines of error here
}
if (type & MOUSE) {
addMouseCallback(hwnd, f); // The same here
}
}
private:
void addDisplayCallback(int hwnd, boost::function<void ()> f) {
_display_callback[hwnd] = f;
};
void addMouseCallback(int hwnd, boost::function<void (int, int)> f) {
_mouse_callback[hwnd] = f;
};
std::map<int, boost::function<void ()>> _display_callback;
std::map<int, boost::function<void (int, int)>> _mouse_callback;
};
我将这些功能称为:
CallBackManager cbm;
cbm.AddCallBack(
CallBackManager::CallBackType::DISPLAY,
my_handle,
boost::bind(&Foo::Display, this)); // boost::function<void ()>
cbm.AddCallback(
CallBackManager::CallBackType::DISPLAY,
my_handle,
boost::bind(&Foo::Mouse, this, _1, _2)): //boost::function<void (int, int)>
最后错误是:
error C2784: 'T &boost::_bi::list0::operator [](const boost::reference_wrapper<T> &) const' : could not deduce template argument C:\local\boost_1_57_0_b1\boost\bind\bind.hpp 392
我不明白这个错误
(这是包含编译错误的代码) https://ideone.com/BdW1Ln
答案 0 :(得分:0)
您在同一个静态代码路径中将T
类型的函数添加到两个映射中。当然,你过滤它,但那是运行时。这无效。
只需使用单独的功能。
它更短,更易读。
<强> Live On Coliru 强>
#include <boost/function.hpp>
#include <boost/bind.hpp>
#include <map>
class CallBackManager {
public:
enum CallBackType { DISPLAY = 1 << 0, MOUSE = 1 << 1 };
struct display_callback_t;
template <typename F>
void AddDisplayCallback(int hwnd, F f) {
addDisplayCallback(hwnd, f);
}
template <typename F>
void AddMouseCallback(int hwnd, F f) {
addMouseCallback(hwnd, f);
}
void test() {
for (auto& f : _display_callback)
f.second();
for (auto& f : _mouse_callback)
f.second(rand(), rand());
}
private:
void addDisplayCallback(int hwnd, boost::function<void()> f) { _display_callback[hwnd] = f; };
void addMouseCallback(int hwnd, boost::function<void(int, int)> f) { _mouse_callback[hwnd] = f; };
std::map<int, boost::function<void()>> _display_callback;
std::map<int, boost::function<void(int, int)>> _mouse_callback;
};
#include <iostream>
struct Foo {
int my_handle;
CallBackManager cbm;
Foo()
{
cbm.AddDisplayCallback(my_handle, boost::bind(&Foo::Display, this));
cbm.AddMouseCallback(my_handle, boost::bind(&Foo::Mouse, this, _1, _2));
}
void Mouse(int, int) {
std::cout << __PRETTY_FUNCTION__ << "\n";
}
void Display() {
std::cout << __PRETTY_FUNCTION__ << "\n";
}
};
int main() {
Foo instance;
instance.cbm.test();
}
打印
void Foo::Display()
void Foo::Mouse(int, int)