hash_multimap::find

返回解决一元素的第一位置的。具有键等效于指定的键的 hash_multimap 的迭代器。

iterator find( 
   const Key& _Key 
); 
const_iterator find( 
   const Key& _Key 
) const;

参数

• _Key
  一元素的排序关键字将匹配的键从搜索的 hash_multimap 的。

返回值

解决一元素第一个位置具有指定键的迭代器或成功个元素的位置。hash_multimap，如果与对于找到键。

备注

成员函数返回解决在 hash_multimap 的元素排序关键字是对 equivalent 参数键在二进制谓词下比可比性关系会基于顺序较少的迭代器。

如果 查找 的返回值分配为 const_iterator，不能修改 hash_multimap 对象。 如果 查找 的返回值赋给 迭代器，可以修改 hash_multimap 对象。

在Visual C++ .NET 2003中，成员<hash_map> 和 <hash_set> 头文件不再在std命名空间，而是已经进入了stdext命名空间。 有关更多信息，请参见 stdext 命名空间。

示例

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

int main()
{
    using namespace std;
    using namespace stdext;
    hash_multimap<int, int> hm1;
    hash_multimap<int, int> :: const_iterator hm1_AcIter, hm1_RcIter;
    typedef pair<int, int> Int_Pair;

    hm1.insert(Int_Pair(1, 10));
    hm1.insert(Int_Pair(2, 20));
    hm1.insert(Int_Pair(3, 20));
    hm1.insert(Int_Pair(3, 30));

    hm1_RcIter = hm1.find(2);
    cout << "The element of hash_multimap hm1 with a key of 2 is: "
          << hm1_RcIter -> second << "." << endl;

    hm1_RcIter = hm1.find(3);
    cout << "The first element of hash_multimap hm1 with a key of 3 is: "
          << hm1_RcIter -> second << "." << endl;

    // If no match is found for the key, end() is returned
    hm1_RcIter = hm1.find(4);

    if (hm1_RcIter == hm1.end())
        cout << "The hash_multimap hm1 doesn't have an element "
             << "with a key of 4." << endl;
    else
        cout << "The element of hash_multimap hm1 with a key of 4 is: "
             << hm1_RcIter -> second << "." << endl;

    // The element at a specific ___location in the hash_multimap can be
    // found using a dereferenced iterator addressing the ___location
    hm1_AcIter = hm1.end();
    hm1_AcIter--;
    hm1_RcIter = hm1.find(hm1_AcIter -> first);
    cout << "The first element of hm1 with a key matching"
         << endl << "that of the last element is: "
         << hm1_RcIter -> second << "." << endl;

    // Note that the first element with a key equal to
    // the key of the last element is not the last element
    if (hm1_RcIter == --hm1.end())
        cout << "This is the last element of hash_multimap hm1."
             << endl;
    else
        cout << "This is not the last element of hash_multimap hm1."
             << endl;
}

要求

标头: <hash_map>

**命名空间：**stdext

请参见

参考

hash_multimap 类

标准模板库