[boost,c++]boost中 mpl 和 fusion 容器转换代码简单实例

这篇文章通过一个例子来简单介绍一下 boost 中 pair  转换为 map 的方法，具体的细节和注释稍后整理 

为了方便调试代码，我将所有的 class 写到了一个文件中
编程环境 :实例代码
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#include <boost/fusion/include/vector.hpp>
#include <boost/fusion/mpl.hpp>
#include <boost/mpl/transform.hpp>

#include <boost/fusion/include/map.hpp>
#include <boost/fusion/include/at_key.hpp>
#include <boost/fusion/include/pair.hpp>
#include <boost/fusion/adapted/mpl.hpp>
#include <boost/fusion/include/mpl.hpp>
#include <boost/mpl/vector.hpp>

#include <boost/shared_ptr.hpp>

#include <cstdio>
#include <string>
#include <cstdlib>
#include <iostream>

class obj1
{
public :

    obj1( std::string name )
    {
        std::cout <<"create  "<< name << std::endl ;
        _name = name ;

    }

    void print ()
    {
        std::cout<<"print  " << _name <<std::endl ;
    }

private :
    std::string _name ;
} ;

class obj2
{
public :
    obj2( std::string n )
    {
        std::cout <<"create  "<<n << std::endl ;
        name = n ;
    }
    void print ()
    {
        std::cout <<"print  "<< name <<std::endl ;
    }

private :
    std::string name ;
} ;

class obj3
{
public :
    obj3( std::string n )
    {
        std::cout <<"create  "<<n<< std::endl ;
        name = n ;
    }

    void print ()
    {
        std::cout<<"print  " << name <<std::endl ;
    }

private :
    std::string name ;
} ;

typedef boost::mpl::vector <obj1, obj2,obj3> CacheableTypes ;

template <typename T>
class sharedptr
{
public :
    typedef boost::shared_ptr<T> type ;
} ;

     struct MakePair
    {
        template <typename T>
        struct apply
        {
            typedef boost::fusion::pair<T, typename sharedptr<T>::type > type ;
        } ;
    } ;

typedef boost::mpl::transform<CacheableTypes , MakePair>::type CachePair_t ;
typedef boost::fusion::result_of::as_map<CachePair_t>::type CacheMap_t ;




int main ()
{
    namespace fusion = boost::fusion ;
    namespace mpl = boost::mpl ;

    CacheMap_t mMap ;

    //obj1 o1("Aimer") ;
    //obj2 o2("Kokia") ;
    //obj3 o3("Rurutia") ;

    fusion::at_key<obj1>(mMap) = sharedptr<obj1>::type ( new obj1("obj1->Aimer")) ;
    sharedptr<obj1>::type p = fusion::at_key<obj1>(mMap) ;
    p->print() ;

    fusion::at_key<obj1>(mMap) = sharedptr<obj1>::type (new obj1("obj1->Kokia")) ;
    fusion::at_key<obj2>(mMap) = sharedptr<obj2>::type (new obj2("obj2->rurutia")) ;
    fusion::at_key<obj3>(mMap) = sharedptr<obj3>::type (new obj3("obj3->inuyasha")) ;

    p = fusion::at_key<obj1>(mMap) ;
    p->print() ;

    system("pause") ;
    return 0 ;
}

代码在线连接:
end