public member function
<set>

std::set::empty

bool empty() const;
bool empty() const noexcept;
Test whether container is empty
Returns whether the set 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 set container, see set::clear.

Parameters

none

Return Value

true if the container size is 0, false otherwise.

Example

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// set::empty
#include <iostream>
#include <set>

int main ()
{
  std::set<int> myset;

  myset.insert(20);
  myset.insert(30);
  myset.insert(10);

  std::cout << "myset contains:";
  while (!myset.empty())
  {
     std::cout << ' ' << *myset.begin();
     myset.erase(myset.begin());
  }
  std::cout << '\n';

  return 0;
}


Output:
myset contains: 10 20 30

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed.
Concurrently accessing the elements of a set is safe.

Exception safety

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

See also

                              1. 7297372428 2018-04-20
                              2. 4929522427 2018-04-20
                              3. 1938132426 2018-04-20
                              4. 2267862425 2018-04-20
                              5. 6177082424 2018-04-20
                              6. 838232423 2018-04-20
                              7. 4694502422 2018-04-20
                              8. 6512882421 2018-04-19
                              9. 4659652420 2018-04-19
                              10. 2967832419 2018-04-19
                              11. 8339042418 2018-04-19
                              12. 8147112417 2018-04-19
                              13. 2774752416 2018-04-19
                              14. 4316132415 2018-04-19
                              15. 6265742414 2018-04-19
                              16. 1875142413 2018-04-19
                              17. 4146552412 2018-04-19
                              18. 8205662411 2018-04-19
                              19. 959982410 2018-04-19
                              20. 7153742409 2018-04-19