set::begin
Returns an iterator that addresses the first element in the set.
const_iterator begin( ) const;
iterator begin( );
Return Value
A bidirectional iterator addressing the first element in the set or the location succeeding an empty set.
Remarks
If the return value of begin is assigned to a const_iterator, the elements in the set object cannot be modified. If the return value of begin is assigned to an iterator, the elements in the set object can be modified.
Example
// set_begin.cpp
// compile with: /EHsc
#include <set>
#include <iostream>
int main( )
{
using namespace std;
set <int> s1;
set <int>::iterator s1_Iter;
set <int>::const_iterator s1_cIter;
s1.insert( 1 );
s1.insert( 2 );
s1.insert( 3 );
s1_Iter = s1.begin( );
cout << "The first element of s1 is " << *s1_Iter << endl;
s1_Iter = s1.begin( );
s1.erase( s1_Iter );
// The following 2 lines would err because the iterator is const
// s1_cIter = s1.begin( );
// s1.erase( s1_cIter );
s1_cIter = s1.begin( );
cout << "The first element of s1 is now " << *s1_cIter << endl;
}
The first element of s1 is 1 The first element of s1 is now 2
Requirements
Header: <set>
Namespace: std