deque::begin
Returns an iterator addressing the first element in the deque.
const_iterator begin( ) const;
iterator begin( );
Return Value
A random-access iterator addressing the first element in the deque or to the location succeeding an empty deque.
Remarks
If the return value of begin is assigned to a const_iterator, the deque object cannot be modified. If the return value of begin is assigned to an iterator, the deque object can be modified.
Example
// deque_begin.cpp
// compile with: /EHsc
#include <deque>
#include <iostream>
int main( )
{
using namespace std;
deque <int> c1;
deque <int>::iterator c1_Iter;
deque <int>::const_iterator c1_cIter;
c1.push_back( 1 );
c1.push_back( 2 );
c1_Iter = c1.begin( );
cout << "The first element of c1 is " << *c1_Iter << endl;
*c1_Iter = 20;
c1_Iter = c1.begin( );
cout << "The first element of c1 is now " << *c1_Iter << endl;
// The following line would be an error because iterator is const
// *c1_cIter = 200;
}
Output
The first element of c1 is 1
The first element of c1 is now 20
Requirements
Header: <deque>
Namespace: std