学步园

any是任意对象。配合使用STL容器点，可向此容器添加任意类型的对象。

#include <iostream>
#include <string>
#include <utility>
#include <vector>
#include "boost/any.hpp"
using namespace std;

class A{
public:
     void some_function(){
         cout << "A::some_function()" << endl;
     }
 };
 
 class B{
 public:
     void some_function(){
         cout << "B::some_function()" << endl;
     }
 };
 
 class C{
 public:
     void some_function(){
         cout << "C::some_function()" << endl;
     }
 };
 
 void print_any(boost::any& a){
     if(A* pA = boost::any_cast<A>(&a))
     {
         pA->some_function();
     }
     else if(B* pB = boost::any_cast<B>(&a))
     {
         pB->some_function();
     }
     else if(C* pC = boost::any_cast<C>(&a))
     {
         pC->some_function();
     }
 }
 
 int main(){
     cout << "Example of using any" << endl;
     vector<boost::any> store_anything;
 
     store_anything.push_back(A());
     store_anything.push_back(B());
     store_anything.push_back(C());
 
     store_anything.push_back(string("This is great!"));
     store_anything.push_back(3);
     store_anything.push_back(make_pair(true, 7.92));
 
     void print_any(boost::any& a);
 
     for_each(store_anything.begin(), store_anything.end(), print_any);
 
     cin.get();
 }