home | help 
std::unorde...imap::empty(3)   C++ Standard Libary  std::unorde...imap::empty(3)

NAME
     std::unordered_multimap::empty - std::unordered_multimap::empty

Synopsis
	bool empty() const noexcept;		    (since C++11)
						    (until C++20)
	[[nodiscard]] bool empty() const noexcept;  (since C++20)

	Checks if the container has no elements, i.e. whether begin() == end().

Parameters
	(none)

Return value
	true if the container is empty, false otherwise.

Complexity
	Constant.

Example
	The following code uses empty to check if a std::unordered_multimap<int,
     int>
	contains any elements:

     // Run this code

      #include <iostream>
      #include <unordered_map>
      #include <utility>

      int main()
      {
	  std::unordered_multimap<int,int> numbers;
	  std::cout << std::boolalpha;
	  std::cout  <<  "Initially,  numbers.empty():	"  << numbers.empty() <<
     '\n';

	  numbers.emplace(42, 13);
	  numbers.insert(std::make_pair(13317, 123));
	  std::cout <<	"After	adding	elements,  numbers.empty():  "	<<  num-
     bers.empty() << '\n';
      }

Output:
      Initially, numbers.empty(): true
      After adding elements, numbers.empty(): false

See also
	size	returns the number of elements
		(public member function)
	empty	checks whether the container is empty
	(C++17) (function template)

http://cppreference.com 	   2024.06.10	    std::unorde...imap::empty(3)
home | help