sizeof( vector<> ）

#include <iostream.h> 

#include <vector> 

 

using namespace std; 

 

struct Node 

{ 

int id; 

vector<int> score; 

}; 

 

void DisplayVector(vector<int> &v) 

{ 

cout<<"sizeof(v) = "<<sizeof(v)<<endl; 

for(vector<int>::iterator it = v.begin(); it != v.end(); it++) 

{ 

cout<<*it<<'\t'; 

} 

cout<<endl; 

} 

 

void DisplaySize() 

{ 

cout<<"sizeof(vector<char>) = "<<sizeof(vector<char>)<<endl; 

cout<<"sizeof(vector<int>) = "<<sizeof(vector<int>)<<endl; 

cout<<"sizeof(vector<short>) = "<<sizeof(vector<short>)<<endl; 

cout<<"sizeof(vector<double>) = "<<sizeof(vector<double>)<<endl; 

cout<<"sizeof(vector<long>) = "<<sizeof(vector<long>)<<endl; 

cout<<"sizeof(vector<float>) = "<<sizeof(vector<float>)<<endl; 

} 

 

int main() 

{ 

DisplaySize(); 

 

Node node; 

cout<<"sizeof(Node) = "<<sizeof(node)<<endl; 

 

node.id = 1; 

node.score.push_back(10); 

node.score.push_back(20); 

node.score.push_back(25); 

cout<<"sizeof(Node) = "<<sizeof(node)<<endl; 

 

DisplayVector(node.score); 

 

return 0; 

} 

 

输出结果：

sizeof(vector<char>) = 16
sizeof(vector<int>) = 16
sizeof(vector<short>) = 16
sizeof(vector<double>) = 16
sizeof(vector<long>) = 16
sizeof(vector<float>) = 16
sizeof(Node) = 20
sizeof(Node) = 20
sizeof(v) = 16
10 20 25

 

 

不管插入多少数据，sizeof(vector<>)大小不变，在vc下始终为16，在vs下据说20