返回迭代器到与一键比指定的键大的基于的第一个元素。
iterator upper_bound(
const Key& _Key
);
const_iterator upper_bound(
const Key& _Key
) const;
参数
- _Key
参数键与一个元素的排序关键字进行比较从要搜索的基于的。
返回值
解决一个元素位置在基于与键比参数键大的一个迭代或 const_iterator 或解决成功最后一个元素的位置在基于匹配项,则也没有为键中。
如果返回值赋给 const_iterator,不能修改基于对象。如果返回值赋给 iterator,可以修改基于对象。
示例
// multimap_upper_bound.cpp
// compile with: /EHsc
#include <map>
#include <iostream>
int main( )
{
using namespace std;
multimap <int, int> m1;
multimap <int, int> :: const_iterator m1_AcIter, m1_RcIter;
typedef pair <int, int> Int_Pair;
m1.insert ( Int_Pair ( 1, 10 ) );
m1.insert ( Int_Pair ( 2, 20 ) );
m1.insert ( Int_Pair ( 3, 30 ) );
m1.insert ( Int_Pair ( 3, 40 ) );
m1_RcIter = m1.upper_bound( 1 );
cout << "The 1st element of multimap m1 with "
<< "a key greater than 1 is: "
<< m1_RcIter -> second << "." << endl;
m1_RcIter = m1.upper_bound( 2 );
cout << "The first element of multimap m1 with a key "
<< " greater than 2 is: "
<< m1_RcIter -> second << "." << endl;
// If no match is found for the key, end( ) is returned
m1_RcIter = m1.lower_bound( 4 );
if ( m1_RcIter == m1.end( ) )
cout << "The multimap m1 doesn't have an element "
<< "with a key of 4." << endl;
else
cout << "The element of multimap m1 with a key of 4 is: "
<< m1_RcIter -> second << "." << endl;
// The element at a specific ___location in the multimap can be
// found using a derefenced iterator addressing the ___location
m1_AcIter = m1.begin( );
m1_RcIter = m1.upper_bound( m1_AcIter -> first );
cout << "The first element of m1 with a key greater than\n"
<< "that of the initial element of m1 is: "
<< m1_RcIter -> second << "." << endl;
}
要求
标头: <map>
命名空间: std