C++声明一组函数指针

Question

基本上我需要实现一个事件处理程序类,但遇到一个错误,我不能声明一个空洞数组:

class SomeClass
{
public:
    void registerEventHandler(int event, void (*handler)(std::string));

private:
    // here i get this error: declaration of ‘eventHandlers’ as array of void
    void (*eventHandlers)(std::string)[TOTAL_EVENTS];
}

void SomeClass::registerEventHandler(int event, void (*handler)(std::string))
{
    eventHandlers[event] = handler;
}



void handler1(std::string response)
{
    printf("ON_INIT_EVENT handler\n");
}
void handler2(std::string response)
{
    printf("ON_READY_EVENT handler\n");
}

void main()
{
    someClass.registerEventHandler(ON_INIT_EVENT, handler1);
    someClass.registerEventHandler(ON_READY_EVENT, handler2);
}

你能帮我弄清楚确切的语法吗？谢谢!

Answer 1

这不是空洞的数组.它是函数指针的数组.您应该按如下方式定义它:

void (*eventHandlers[TOTAL_EVENTS])(std::string);

或者更好(C++ 14):

using event_handler = void(*)(std::string);
event_handler handlers[TOTAL_EVENTS];

或者C++ 03:

typedef void(*event_handler)(std::string);
event_handler handlers[TOTAL_EVENTS];

但我宁愿建议使用矢量:

using event_handler = void(*)(std::string);
std::vector<event_handler> handlers;