public member function
<set>

std::set::clear

void clear();
void clear() noexcept;
Clear content
Removes all elements from the set container (which are destroyed), leaving the container with a size of0.

参数



返回值



示例

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

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

  myset.insert (100);
  myset.insert (200);
  myset.insert (300);

  std::cout << "myset contains:";
  for (std::set<int>::iterator it=myset.begin(); it!=myset.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  myset.clear();
  myset.insert (1101);
  myset.insert (2202);

  std::cout << "myset contains:";
  for (std::set<int>::iterator it=myset.begin(); it!=myset.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}

输出
myset contains: 100 200 300
myset contains: 1101 2202


复杂度

Linear in size (destructions).

迭代器有效性

所有与该容器相关的迭代器、指针和引用都将失效。

数据竞争

The container is modified.
所有包含的元素都被修改。

异常安全

无异常保证:此成员函数从不抛出异常。

另见