C++中assign的用法

转载自：http://blog.163.com/chen_dawn/blog/static/112506320112953921372/

vector::assign //用来构造一个vector的函数，类似于copy函数

void assign( size_type _Count, const Type&
_Val);

//_Count指要构造的vector成员的个数，   _Val指成员的数值，他的类型必须与vector类型一致！ 
template<class InputIterator> 
void assign( InputIterator _First, InputIterator _Last ); 
//两个指针，分别指向复制开始和结束的地方! 
EXAMPLE
// vector_assign.cpp
// compile with: /EHsc
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   vector<int> v1, v2, v3;
   vector<int>::iterator iter;

   v1.push_back(10);
   v1.push_back(20);
   v1.push_back(30);
   v1.push_back(40);
   v1.push_back(50);

   cout << "v1 = " ;
   for (iter = v1.begin(); iter != v1.end(); iter++)
       cout << *iter << " ";
   cout << endl;

   v2.assign(v1.begin(), v1.end());
   cout << "v2 = ";
   for (iter = v2.begin(); iter != v2.end(); iter++)
       cout << *iter << " ";
   cout << endl;

   v3.assign(7, 4) ;
   cout << "v3 = ";
   for (iter = v3.begin(); iter != v3.end(); iter++)
       cout << *iter << " ";
   cout << endl;
}
输出结果为：
v1 = 10 20 30 40 50 
v2 = 10 20 30 40 50 
v3 = 4 4 4 4 4 4 4