public member function
<unordered_set>

std::unordered_multiset::size

size_type size() const noexcept;
Return container size
Returns the number of elements in the unordered_multiset container.

参数



返回值

容器中的元素数量。

成员类型size_type是一种无符号整型类型。

示例

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

int main ()
{
  std::unordered_multiset<std::string> myset;
  std::cout << "0. size: " << myset.size() << std::endl;

  myset = {"house","parking","office"};
  std::cout << "1. size: " << myset.size() << std::endl;

  myset.insert ("house");
  std::cout << "2. size: " << myset.size() << std::endl;

  myset.erase ("house");
  std::cout << "3. size: " << myset.size() << std::endl;

  return 0;
}

输出
0. size: 0
1. size: 3
2. size: 4
3. size: 2


复杂度

常量。

迭代器有效性

没有变化。

另见