hash_multimap::erase

说明说明

此 API 已过时。另一种方法是 unordered_multimap Class

从指定的位置移除元素或元素的大小 hash_multimap 的或移除与指定的键的元素。

iterator erase(
   iterator _Where
);
iterator erase(
   iterator _First,
   iterator _Last
);
size_type erase(
   const key_type& _Key
);

参数

  • _Where
    从 hash_multimap 要移除的元素的位置。

  • _First
    从 hash_multimap 移除的第一个元素的位置。

  • _Last
    在从 hash_multimap 移除的最后一个元素之外标识。

  • _Key
    从 hash_multimap 要移除的元素的键。

返回值

对于前两个成员函数、指定保持在所有元素外的第一个元素中移除一双向迭代器或对 hash_multimap 的末尾的指针,如果不存在这样的元素。

为第三个成员函数,返回从 hash_multimap 中移除了元素的数目。

备注

成员函数从不引发异常。

在 Visual C++ .NET 2003 中,<hash_map><hash_set> 标头文件的成员中不再标准,命名空间,而是将 stdext 命名空间。有关更多信息,请参见 stdext 命名空间

示例

当编译此示例与 /Wp64 标记或在 64 位平台时,警告的编译器 C4267 将生成。有关此警告的更多信息,请参见 编译器警告(等级 3)C4267

// hash_multimap_erase.cpp
// compile with: /EHsc
#include <hash_map>
#include <iostream>

int main()
{
    using namespace std;
    using namespace stdext;
    hash_multimap<int, int> hm1, hm2, hm3;
    hash_multimap<int, int> :: iterator pIter, Iter1, Iter2;
    int i;
    hash_multimap<int, int>::size_type n;
    typedef pair<int, int> Int_Pair;

    for (i = 1; i < 5; i++)
    {
        hm1.insert(Int_Pair (i, i) );
        hm2.insert(Int_Pair (i, i*i) );
        hm3.insert(Int_Pair (i, i-1) );
    }

    // The 1st member function removes an element at a given position
    Iter1 = ++hm1.begin();
    hm1.erase(Iter1);

    cout << "After the 2nd element is deleted, "
         << "the hash_multimap hm1 is:";
    for (pIter = hm1.begin(); pIter != hm1.end(); pIter++)
        cout << " " << pIter -> second;
    cout << "." << endl;

    // The 2nd member function removes elements
    // in the range [_First, _Last)
    Iter1 = ++hm2.begin();
    Iter2 = --hm2.end();
    hm2.erase(Iter1, Iter2);

    cout << "After the middle two elements are deleted, "
         << "the hash_multimap hm2 is:";
    for (pIter = hm2.begin(); pIter != hm2.end(); pIter++)
        cout << " " << pIter -> second;
    cout << "." << endl;

    // The 3rd member function removes elements with a given _Key
    hm3.insert(Int_Pair (2, 5));
    n = hm3.erase(2);

    cout << "After the element with a key of 2 is deleted,\n"
         << " the hash_multimap hm3 is:";
    for (pIter = hm3.begin(); pIter != hm3.end(); pIter++)
        cout << " " << pIter -> second;
    cout << "." << endl;

    // The 3rd member function returns the number of elements removed
    cout << "The number of elements removed from hm3 is: "
         << n << "." << endl;

    // The dereferenced iterator can also be used to specify a key
    Iter1 = ++hm3.begin();
    hm3.erase(Iter1);

    cout << "After another element with a key equal to that of the"
         << endl;
    cout  << " 2nd element is deleted, "
          << "the hash_multimap hm3 is:";
    for (pIter = hm3.begin(); pIter != hm3.end(); pIter++)
        cout << " " << pIter -> second;
    cout << "." << endl;
}
  
  
  
  
  

要求

标头: <hash_map>

命名空间: stdext

请参见

参考

hash_multimap Class

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