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std::deque<T,Allocator>:: pop_back

From cppreference.net

C++
Containers library
std::deque
Member types
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_back ( ) ;
(constexpr since C++26)

Removes the last 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)

Iterators and references to the last element are invalidated. The end() iterator is also invalidated.

Complexity

Constant.

Example

Run this code 
#include <deque>
#include <iostream>
namespace stq
{
    template<typename T>
    void println(auto, const T& xz)
    {
        std::cout << '[';
        bool first{true};
        for (const auto& x : xz)
            std::cout << (first ? first = false, "" : ", ") << x;
        std::cout << "]\n";
    }
}
int main()
{
    std::deque<int> numbers{1, 2, 3};
    stq::println("{}", numbers);
    while (not numbers.empty())
    {
        numbers.pop_back();
        stq::println("{}", numbers);
    }
}

Output: 

[1, 2, 3]
[1, 2]
[1]
[]

See also

removes the first element
(public member function)
adds an element to the end
(public member function)