先来看看如何赋值把:
#include <iostream> #include <vector> #include <string> #include<deque> #include <set> #include <map> #include <boost/assign.hpp> using namespace std; int _tmain(int argc, _TCHAR* argv[]) { using namespace boost::assign; //使用list_of vector<int> v=list_of(1)(2)(3)(4)(5); deque<string>d=(list_of("hello")("rollen")); set<int>s=(list_of(10),20,30,40); map<int, string>m=list_of(make_pair(1,"hello"))(make_pair(2,"rollen")); //list_of可以全部使用括号,也可以将括号和逗号一起使用,但是对于后者需要 // 将整个lits_of用括号括起来。否则编译器无法推导出list_of的类型而无法赋值。 // 下面使用map_list_of 和pair_list_of map<int,int>mp=map_list_of(1,1)(2,2)(3,3); map<int,string>mp2=pair_list_of(1,"hello")(2,"rollen"); //其实还有tuple_list_of }
#include <iostream> #include <vector> #include <string> #include<deque> #include <set> #include <map> #include <multiset> #include <boost/assign.hpp> using namespace std; //减少重复输入 int _tmain(int argc, _TCHAR* argv[]) { using namespace boost::assign; vector<int>v=list_of(1).repeat(2,3)(4)(5); //将3重复2次 //v=1,3,3,4,5 multiset<int>ms; insert(ms).repeat_fun(5,&rand).repeat(2,1),10; //ms=x,x,x,x,x,1,1,10 deque<int>d; push_front(d).range(v.begin(),v.end()); //将一个序列的元素插入另外一个序列 //d=1,3,3,4,5 }
与非标准容器一起使用
#include <iostream> #include <vector> #include <string> #include <stack> #include <queue> #include <boost/assign.hpp> using namespace std; //与非标准容器一起使用 int _tmain(int argc, _TCHAR* argv[]) { using namespace boost::assign; stack<int>s=(list_of(1),2,3).to_adapter(); while(!s.empty()){ cout<<s.top()<<" "; s.pop(); } cout<<endl; queue<string>q=(list_of("hello")("rollen").repeat(2,"holt")).to_adapter(); while(!q.empty()){ cout<<q.front()<<" "; q.pop(); } cout<<endl; priority_queue<double>pq=(list_of(1.21)(2.23)).to_adapter(); while(!pq.empty()){ cout<<pq.top()<<" "; pq.pop(); } cout<<endl; }
assign也支持部分不在STL中定义的非标准容器,比如slist和hash_map hash_set 用法和标准容器一样、
此外,assign也支持大部分Boost的库容器
#include <iostream> #include <vector> #include <string> #include <boost/assign.hpp> using namespace std; //list_of的嵌套使用 // 构建二维数组 int _tmain(int argc, _TCHAR* argv[]) { using namespace boost::assign; vector<vector<int> >v=list_of(list_of(1)(2))(list_of(3)(4)); v+=list_of(5)(6),list_of(7)(8); int a=1,b=2,c=3; vector<int>v1=cref_list_of<3>(a)(b)(c); //也可以使用ref_list_of assert(v.size()==3); }
#include <boost/swap.hpp> using namespace std; //交换两个数组,两个数组的长度必须一致 int _tmain(int argc, _TCHAR* argv[]) { int a1[10]; int a2[10]; std::fill_n(a1,10,1); std::fill_n(a2,10,2); boost::swap(a1,a2); }
特化 swap
#include <iostream> #include <vector> #include <string> #include <boost/swap.hpp> using namespace std; class point{ public: explicit point(int a,int b,int c):x(a),y(b),z(c){} void print()const{ cout<<x<<" "<<y<<" "<<z<<endl; } void swap(point &p){ std::swap(x,p.x); std::swap(y,p.y); std::swap(z,p.z); cout<<"inner swap"<<endl; } private: int x,y,z; }; //特化std::swap 原则上不能动std namespace std{ template<> void swap(point &x,point &y){ x.swap(y); } } int _tmain(int argc, _TCHAR* argv[]) { point a(1,2,3); point b(4,5,6); cout<<"std swap"<<endl; std::swap(a,b); cout<<"boost swap"<<endl; boost::swap(a,b); }
由于我们特化了swap,因此boost::swap 和std::swap效果一样
特化ADL可找到的swap
#include <iostream> #include <vector> #include <string> #include <boost/swap.hpp> using namespace std; class point{ public: explicit point(int a,int b,int c):x(a),y(b),z(c){} void print()const{ cout<<x<<" "<<y<<" "<<z<<endl; } void swap(point &p){ std::swap(x,p.x); std::swap(y,p.y); std::swap(z,p.z); cout<<"inner swap"<<endl; } private: int x,y,z; }; void swap(point &x,point &y){ x.swap(y); } int _tmain(int argc, _TCHAR* argv[]) { point a(1,2,3); point b(4,5,6); cout<<"std swap"<<endl; std::swap(a,b); cout<<"boost swap"<<endl; boost::swap(a,b); }
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本文转自被遗忘的博客园博客,原文链接:http://www.cnblogs.com/rollenholt/archive/2012/03/27/2419217.html,如需转载请自行联系原作者