public member function
<map>

std::multimap::empty

bool empty() const;
bool empty() const noexcept;
Test whether container is empty
Returns whether the multimap container is empty (i.e. whether its size is 0).

This function does not modify the container in any way. To clear the content of a multimap container, see multimap::clear.

Parameters

none

Return Value

true if the container size is 0, false otherwise.

Example

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// multimap::empty
#include <iostream>
#include <map>

int main ()
{
  std::multimap<char,int> mymultimap;

  mymultimap.insert (std::pair<char,int>('b',101));
  mymultimap.insert (std::pair<char,int>('b',202));
  mymultimap.insert (std::pair<char,int>('q',505));

  while (!mymultimap.empty())
  {
     std::cout << mymultimap.begin()->first << " => ";
     std::cout << mymultimap.begin()->second << '\n';
     mymultimap.erase(mymultimap.begin());
  }

  return 0;
}


Output:
b => 101
b => 202
q => 505

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed.
No contained elements are accessed: concurrently accessing or modifying them is safe.

Exception safety

No-throw guarantee: this member function never throws exceptions.

See also

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