Designates the beginning of the controlled sequence or a bucket.
const_iterator cbegin() const;
Remarks
The member function returns a const forward iterator that points at the first element of the sequence (or just beyond the end of an empty sequence).
Example
// std_tr1__unordered_map__unordered_map_cbegin.cpp
// compile with: /EHsc
#include <unordered_map>
#include <iostream>
typedef std::unordered_map<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);
}
[c, 3] [b, 2] [a, 1] [c, 3] [b, 2]
Requirements
Header: <unordered_map>
Namespace: std