boost 数据结构

#include <boost/tuple/tuple.hpp> #include <boost/tuple/tuple_io.hpp>

#include <boost/tuple/tuple_comparison.hpp>

//tuple(元组),他和std::pair类似,只是他不仅仅存储一对数据,可以存储无限多个数据//tuple使其支持流的输出,需要包含 #include <boost/tuple/tuple_io.hpp>typedef boost::tuple<std::string,std::string,int> person;std::stringstream strstream;person per("hello","hi",32);strstream << per;TRACE("%s\n",strstream.str().c_str());//(hello hi 32)//boost::make_tuple{person per=boost::make_tuple("hello","hi",32);strstream.str("");//stringstream 清除缓冲区 只能使用strstream.str("");如果使用strstream.clear(),strstream.str().clear() 也是么有效果的strstream<<per;TRACE("%s\n",strstream.str().c_str());string szName="name";//引用值传递person per2=boost::make_tuple(boost::ref(szName),"hi",32);strstream.str("");strstream<<per2;TRACE("%s\n",strstream.str().c_str());}//如何访问tuple的元素{person per=boost::make_tuple("hello","hi",32);strstream.str("");strstream<<per.get<0>();TRACE("%s\n",strstream.str().c_str());//hello//第二种访问方式strstream.str("");strstream<< boost::get<2>(per);TRACE("%s\n",strstream.str().c_str());//32//get() 和 boost::get() 都会返回一个引用值,所以我们可以对其进行修改值boost::get<2>(per)=33;strstream.str("");strstream<<boost::get<2>(per);TRACE("%s\n",strstream.str().c_str());//33}//比较操作,需要包含 boost/tuple/tuple_comparison.hpp{person p1 = boost::make_tuple("AA", "BB", 43); person p2 = boost::make_tuple("AA", "BB", 43); TRACE("%d\n",p1 != p2);}//boost::tie 使用,比较特殊,他可以引用变量,变量一旦修改他也修改了{//这里定义的记得使用引用类型typedef boost::tuple<std::string&, std::string&, int&> person2; std::string firstname = "AA"; std::string secondname = "BB"; int shoesize = 43; //person p = boost::make_tuple(boost::ref(firstname), boost::ref(surname), boost::ref(shoesize)); //如果不使用boost::tie可以使用原生的替换person2 p = boost::tie(firstname, secondname, shoesize); firstname="DD";secondname = "CC"; shoesize=44;strstream.str("") ;strstream.clear();strstream << p;TRACE("%s\n",strstream.str().c_str());//(DD CC 44)}{string szData;int nData;boost::tie(szData,nData)=func();TRACE("%s,%d\n",szData.c_str(),nData);//Test test,1024}

1.boost::variant

boost::variant<double,char,std::string> v;v=3.14;v='a';v="jks";//最后压入了stringdouble v1=boost::get<double>(v);//这里会抛出一个异常,boost::variant 以最后一个为准char v2=boost::get<char>(v);string v3=boost::get<string>(v);

boost::variant<double,char,std::string> v;v=3.14;v='a';v="jks";//最后压入了stringstring v3=boost::get<string>(v);//提取正确

boost::variant<double,char,std::string> v;//正确运行如下v=3.14;double v1=boost::get<double>(v);v='a';char v2=boost::get<char>(v);v="jks";string v3=boost::get<string>(v);

boost::variant<double,char,std::string> v;v=3.14;v='a';v="jks";//最后压入了stringtry{double v1=boost::get<double>(v);//抛出异常}catch (std::exception& e){TRACE("%s",e.what());}

2.boost::apply_visitor

std::vector<boost::any> vcData; struct output : public boost::static_visitor<> { void operator()(double &d) const { vcData.push_back(d); } void operator()(char &c) const { vcData.push_back(c); } void operator()(std::string &s) const { vcData.push_back(s); } }; void CMFC08Dlg::OnBnClickedButton2(){boost::variant<double, char, std::string> v; v = 3.14; boost::apply_visitor(output(), v); v = 'A'; boost::apply_visitor(output(), v); v = "Hello, world!"; boost::apply_visitor(output(), v); }/*template <typename Visitor, typename Visitable>inline    BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type) //这里是返回一个 Visitor::result_typeapply_visitor(const Visitor& visitor, Visitable& visitable){    return visitable.apply_visitor(visitor);}上面是apply_visitor的函数定义,传递的两个参数都是一个模板的参数,Visitor& visitor(访问者类)Visitable& visitable(支持访问者的类)所以从上面看出我们调用 apply_visitor,满足如下条件即可:1.Visitor& visitor(访问者类),定义了 Visitor::result_type 即可1.static_visitor 源码namespace detail {struct is_static_visitor_tag { };typedef void static_visitor_default_return;//1.重新定义了 void 指向为 static_visitor_default_return} // namespace detailtemplate <typename R = ::boost::detail::static_visitor_default_return> //2.默认的类型是void,所以直接static_visitor<>表示用void类型class static_visitor: public detail::is_static_visitor_tag{public: // typedefstypedef R result_type;//3.将传递进来的类型定义为 result_typeprotected: // for use as base class only#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) && !defined(BOOST_NO_CXX11_NON_PUBLIC_DEFAULTED_FUNCTIONS)static_visitor() = default;~static_visitor() = default;#elsestatic_visitor()  BOOST_NOEXCEPT { }~static_visitor()  BOOST_NOEXCEPT { }#endif};2.Visitable& visitable(支持访问者的类),实现成员函数apply_visitor即可*/

struct output //: public boost::static_visitor<> { typedef void result_type;//所以实现方法二void operator()(double &d) const { vcData.push_back(d); } void operator()(char &c) const { vcData.push_back(c); } void operator()(std::string &s) const { vcData.push_back(s); } };