unordered_set::begin
Designates the beginning of the controlled sequence or a bucket.
iterator begin();
const_iterator begin() const;
local_iterator begin(size_type nbucket);
const_local_iterator begin(size_type nbucket) const;
Parameters
Parameter |
Description |
nbucket |
The bucket number. |
Remarks
The first two member functions return a forward iterator that points at the first element of the sequence (or just beyond the end of an empty sequence). The last two member functions return a forward iterator that points at the first element of bucket nbucket (or just beyond the end of an empty bucket).
Example
// std_tr1__unordered_set__unordered_set_begin.cpp
// compile with: /EHsc
#include <unordered_set>
#include <iostream>
typedef std::unordered_set<char> Myset;
int main()
{
Myset c1;
c1.insert('a');
c1.insert('b');
c1.insert('c');
// display contents " [c] [b] [a]"
for (Myset::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << *it << "]";
std::cout << std::endl;
// inspect first two items " [c] [b]"
Myset::iterator it2 = c1.begin();
std::cout << " [" << *it2 << "]";
++it2;
std::cout << " [" << *it2 << "]";
std::cout << std::endl;
// inspect bucket containing 'a'
Myset::const_local_iterator lit = c1.begin(c1.bucket('a'));
std::cout << " [" << *lit << "]";
return (0);
}
[c] [b] [a] [c] [b] [a]
Requirements
Header: <unordered_set>
Namespace: std