pop_front |
C++ Library |
void pop_front()
Removes an object from the front of the list container. If you call pop_front on an empty list container the results are undefined.
#include <list>
#include <iostream>
#include <functional>
int main()
{
//default constructor
std::list<int> c1 ;
//create list with 10 copies of 4
std::list<int> c2(10, 4) ;
//copy constructor
std::list<int> c3(c2) ;
int ai[] = {0, 1, 2, 3, 4, 5} ;
int i ;
std::list<int> c4 ;
//get_allocator
std::list<int>::allocator_type a1 = c4.get_allocator() ;
//push_back
for(i = 0; i < 5; i++)
c4.push_back(ai[i]) ;
//range copy constructor
std::list<int> c5(c4.begin(), c4.end()) ;
//begin, end
std::cout << "c4 (using begin, end) = " ;
std::list<int>::iterator Iter ;
for(Iter = c4.begin(); Iter != c4.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
//rbegin, rend
std::cout << "c4 (using rbegin, rend) = " ;
std::list<int>::reverse_iterator RevIter ;
for(RevIter = c4.rbegin(); RevIter != c4.rend(); RevIter++)
std::cout << *RevIter << ", " ;
std::cout << std::endl ;
//assign
c2.assign(c5.begin(), c5.end()) ;
c1.assign(10, 4) ;
//back
std::cout << "last element in c2 = " << c2.back() << std::endl ;
//front
std::cout << "first element in c2 = " << c2.front() << std::endl ;
//size
std::cout << "number of elements in c2 = " << c2.size() << std::endl ;
//max_size
std::cout << "max number of elements c2 can hold using current allocator = "
<< c2.max_size() << std::endl ;
//erase
c3.erase(c3.begin(), c3.end()) ;
//clear
c2.clear() ;
//empty
if (c2.empty() == true)
std::cout << "c2 is now empty" << std::endl ;
//resize
c2.resize(10, 30) ;
std::cout << "number of elements in c2 = " << c2.size() << std::endl ;
std::cout << "last element in c2 = " << c2.back() << std::endl ;
std::cout << "first element in c2 = " << c2.front() << std::endl ;
//push_front
c2.push_front(25) ;
std::cout << "first element in c2 = " << c2.front() << std::endl ;
//pop_back
c2.pop_back() ;
std::cout << "last element in c2 = " << c2.back() << std::endl ;
//pop_front
c2.pop_front() ;
std::cout << "first element in c2 = " << c2.front() << std::endl ;
//swap
c3.swap(c2) ;
std::cout << "number of elements in c3 = " << c3.size() << std::endl ;
std::cout << "last element in c3 = " << c3.back() << std::endl ;
std::cout << "first element in c3 = " << c3.front() << std::endl ;
//insert
c1.insert(c1.begin(), 20) ;
c3.insert(c3.begin(), 4, 10) ;
c3.insert(c3.end(), c5.begin(), c5.end()) ;
std::cout << "c1 = " ;
for(Iter = c1.begin(); Iter != c1.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
//reverse
c3.reverse() ;
std::cout << "c3, after reversing = " ;
for(Iter = c3.begin(); Iter != c3.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
//remove
c3.remove(30) ;
std::cout << "c3, after removing all occurences of 30 = " ;
for(Iter = c3.begin(); Iter != c3.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
c2.insert(c2.begin(), 4, 10) ;
//remove_if
c2.remove_if(std::bind2nd(std::not_equal_to<int>(), 10)) ;
std::cout << "c2, after removing all elements which are not equal to 10 = " ;
for(Iter = c2.begin(); Iter != c2.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
c2.insert(c2.begin(), 35) ;
//sort
c3.sort() ;
std::cout << "c3, after sorting = " ;
for(Iter = c3.begin(); Iter != c3.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
//unique
c2.unique() ;
std::cout << "c2, after removing duplicates = " ;
for(Iter = c2.begin(); Iter != c2.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
//splice
c3.splice(c3.end(), c2) ;
c3.splice(c3.end(), c4, c4.begin()) ;
c3.splice(c3.end(), c1, c1.begin(), c1.end()) ;
c3.sort() ;
c3.unique() ;
std::cout << "c3 = " ;
for(Iter = c3.begin(); Iter != c3.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
std::cout << "c2 = " ;
for(Iter = c2.begin(); Iter != c2.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
std::cout << "c1 = " ;
for(Iter = c1.begin(); Iter != c1.end(); Iter++)
std::cout << *Iter << ", " ;
std::cout << std::endl ;
return 0 ;
}
c4 (using begin, end) = 0, 1, 2, 3, 4, c4 (using rbegin, rend) = 4, 3, 2, 1, 0, last element in c2 = 4 first element in c2 = 0 number of elements in c2 = 5 max number of elements c2 can hold using current allocator = 1073741823 c2 is now empty number of elements in c2 = 10 last element in c2 = 30 first element in c2 = 30 first element in c2 = 25 last element in c2 = 30 first element in c2 = 30 number of elements in c3 = 9 last element in c3 = 30 first element in c3 = 30 c1 = 20, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, c3, after reversing = 4, 3, 2, 1, 0, 30, 30, 30, 30, 30, 30, 30, 30, 30, 10, 10, 10, 10, c3, after removing all occurences of 30 = 4, 3, 2, 1, 0, 10, 10, 10, 10, c2, after removing all elements which are not equal to 10 = 10, 10, 10, 10, c3, after sorting = 0, 1, 2, 3, 4, 10, 10, 10, 10, c2, after removing duplicates = 35, 10, c3 = 0, 1, 2, 3, 4, 10, 20, 35, c2 = c1 =