vector::const_reference
提供在 const 項目的參考型別在讀取及執行作業 const 向量中儲存。
typedef typename Allocator::const_reference const_reference;
備註
型別 const_reference 不能用來修改項目的值。
範例
// vector_const_ref.cpp
// compile with: /EHsc
#include <vector>
#include <iostream>
int main( )
{
using namespace std;
vector <int> v1;
v1.push_back( 10 );
v1.push_back( 20 );
const vector <int> v2 = v1;
const int &i = v2.front( );
const int &j = v2.back( );
cout << "The first element is " << i << endl;
cout << "The second element is " << j << endl;
// The following line would cause an error as v2 is const
// v2.push_back( 30 );
}
需求
標題: <vector>
命名空間: std