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      std::deque<T,Allocator>::push_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 push_front(const T& value);
      (1)(constexpr since C++26)
      void push_front( T&& value);
      (2)(since C++11)
      (constexpr since C++26)

      Prepends a copy ofvalue to the beginning of the container.

      All iterators (including theend() iterator) are invalidated. No references are invalidated.

      Contents

      [edit]Parameters

      value - the value of the element to prepend
      Type requirements
      -

      If the following condition is satisfied, the behavior is undefined:

      1)T is notCopyInsertable intodeque.
      2)T is notMoveInsertable intodeque.
      (since C++11)

      [edit]Complexity

      Constant.

      [edit]Exceptions

      If an exception is thrown for any reason, these functions have no effect (strong exception safety guarantee).

      [edit]Example

      Run this code
      #include <deque>#include <iomanip>#include <iostream>#include <string> int main(){std::deque<std::string> letters;     letters.push_front("me");// overload (1)std::string s{"send"};    letters.push_front(std::move(s));// overload (2) std::cout<<"std::deque letters holds: ";for(auto&& e: letters)std::cout<<std::quoted(e)<<' '; std::cout<<"\nMoved-from string s holds: "<<std::quoted(s)<<'\n';}

      Possible output:

      std::deque letters holds: "send" "me"Moved-from string s holds: ""

      [edit]See also

      constructs an element in-place at the beginning
      (public member function)[edit]
      adds an element to the end
      (public member function)[edit]
      removes the first element
      (public member function)[edit]
      creates astd::front_insert_iterator of type inferred from the argument
      (function template)[edit]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/container/deque/push_front&oldid=135183"

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