unordered_multimap::cbegin

项目
02/24/2013

指定控件序列或存储桶的开头。

const_iterator cbegin() const;

备注

成员函数返回指向该序列中的第一个元素的常量向前迭代器 (或在一个空序列之外的结尾)。

示例

// std_tr1__unordered_map__unordered_multimap_cbegin.cpp 
// compile with: /EHsc 
#include <unordered_map> 
#include <iostream> 
 
typedef std::unordered_multimap<char, int> Mymap; 
int main() 
    { 
    Mymap c1; 
 
    c1.insert(Mymap::value_type('a', 1)); 
    c1.insert(Mymap::value_type('b', 2)); 
    c1.insert(Mymap::value_type('c', 3)); 
 
// display contents " [c 3] [b 2] [a 1]" 
    for (Mymap::const_iterator it = c1.cbegin(); 
        it != c1.cend(); ++it) 
        std::cout << " [" << it->first << ", " << it->second << "]"; 
    std::cout << std::endl; 
 
// inspect first two items " [c 3] [b 2]" 
    Mymap::const_iterator it2 = c1.cbegin(); 
    std::cout << " [" << it2->first << ", " << it2->second << "]"; 
    ++it2; 
    std::cout << " [" << it2->first << ", " << it2->second << "]"; 
    std::cout << std::endl; 
    return (0);    }