一个神奇的???whatever~~

一个神奇的类，用来封装消息数据，统一数据传递接口，从unity引擎源码拷贝而来。

#include <iostream>#include <assert.h>#include <crtdefs.h>struct MessageData{int type;private:// Note: on Metro WinRT types cannot be located in union, so don't use union!intptr_t data;public:MessageData (){ data = 0; type = 0; }template<class T>void SetData (T inData, int classId){// Check if SetData is used instead of SetScriptingObjectData //assert (type !=-1);//assert (sizeof (T) > sizeof (data)); // increase the data size*reinterpret_cast<T*> (&data) = *reinterpret_cast<T*> (&inData);type = classId;}template<class T>T GetData (){// Check if GetData is used instead of GetScriptingObjectData assert (type != -1);return *reinterpret_cast<T*> (&data);}intptr_t& GetGenericDataRef (){// Check if GetGenericDataRef is used instead of GetScriptingObjectData assert (type != -1);return data;}};class test{public:test(int x){m_date = x;}void print(){std::cout<<m_date<<std::endl;}private:int m_date ;};int main(){MessageData data;test t(4);data.SetData(&t, 2);test * tt = data.GetData<test*>();tt->print();return 0;}