C++

Reference

<unordered_set>

unordered_multiset

public member type
<unordered_set>

std::unordered_multiset::bucket_size

size_type bucket_size ( size_type n ) const;
Return bucket size
Returns the number of elements in bucket n.

A bucket is a slot in the container's internal hash table to which elements are assigned based on their hash value.

The number of elements in a bucket influences the time it takes to access a particular element in the bucket. The container automatically increases the number of buckets to keep the load factor (which is the average bucket size) below its max_load_factor.

Parameters

n
Bucket number.
This shall be lower than bucket_count.
Member type size_type is an unsigned integral type.

Return Value

The number of elements in bucket n.

Member type size_type is an unsigned integral type.

Example

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// unordered_multiset::bucket_size
#include <iostream>
#include <string>
#include <unordered_set>

int main ()
{
  std::unordered_multiset<std::string> myums =
  {"human","klingon","klingon","vulcan","romulan","cardassian"};

  unsigned nbuckets = myums.bucket_count();

  std::cout << "myums has " << nbuckets << " buckets:\n";

  for (unsigned i=0; i<nbuckets; ++i) {
    std::cout << "bucket #" << i << " has " << myums.bucket_size(i) << " elements.\n";
  }

  return 0;
}

Possible output (the actual number of buckets depends on the library implementation):
myset has 7 buckets:
bucket #0 has 0 elements.
bucket #1 has 0 elements.
bucket #2 has 0 elements.
bucket #3 has 2 elements.
bucket #4 has 0 elements.
bucket #5 has 4 elements.
bucket #6 has 0 elements.


Complexity

Linear in the bucket size.

Iterator validity

No changes.

See also

unordered_multiset::bucket_count
Return number of buckets (public member function)
unordered_multiset::bucket
Locate element's bucket (public member function)
unordered_multiset::size
Return container size (public member function)