list::front
Returns a reference to the first element in a list.
reference front( );
const_reference front( ) const;
Return Value
If the list is empty, the return is undefined.
Remarks
If the return value of front is assigned to a const_reference, the list object cannot be modified. If the return value of front is assigned to a reference, the list object can be modified.
When compiling with _SECURE_SCL 1, a runtime error will occur if you attempt to access an element in an empty list. See Checked Iterators for more information.
Example
// list_front.cpp
// compile with: /EHsc
#include <list>
#include <iostream>
int main() {
using namespace std;
list <int> c1;
c1.push_back( 10 );
int& i = c1.front();
const int& ii = c1.front();
cout << "The first integer of c1 is " << i << endl;
i++;
cout << "The first integer of c1 is " << ii << endl;
}
The first integer of c1 is 10 The first integer of c1 is 11
Requirements
Header: <list>
Namespace: std