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

      From cppreference.com
      <cpp‎ |container‎ |deque

      [edit template]
       
       
       
      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_front();
      (constexpr since C++26)

      Removes the first element of the container.

      Ifempty() istrue, the behavior is undefined.

      (until C++26)

      Ifempty() istrue:

      • If the implementation ishardened, acontract 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 erased element are invalidated. If the element is the last element in the container, theend() iterator is also invalidated. Other references and iterators are not affected.

      [edit]Complexity

      Constant.

      [edit]Example

      Run this code
      #include <deque>#include <iostream> int main(){std::deque<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]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/container/deque/pop_front&oldid=122485"

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