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std::list<T,Allocator>::pop_front

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< cpp‎ | container‎ | list

[edit template]
 
C++
 
Containers library
 
std::list
Member functions
Non-member functions
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides(C++17)
 
void pop_front();
 (constexpr since C++26)

Removes the first element of the container.

If empty() is true, the behavior is undefined.

(until C++26)

If empty() is true:

  • If the implementation is hardened, a contract violation occurs. Moreover, if the contract-violation handler returns under “observe” evaluation semantic, the behavior is undefined.
  • If the implementation is not hardened, the behavior is undefined.
(since C++26)

References and iterators to the erased element are invalidated.

[edit] Complexity

Constant.

[edit] Example

Run this code
#include <list>
#include <iostream>
 
int main()
{
    std::list<char> chars{'A', 'B', 'C', 'D'};
 
    for (; !chars.empty(); chars.pop_front())
        std::cout << "chars.front(): '" << chars.front() << "'\n";
}

Output: 

chars.front(): 'A'
chars.front(): 'B'
chars.front(): 'C'
chars.front(): 'D'

[edit] See also

 removes the last element
(public member function) [edit]
inserts an element to the beginning
(public member function) [edit]
access the first element
(public member function) [edit]
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