set::upper_bound

项目
06/09/2015

返回迭代器在带有密钥大于指定的键的集的第一个元素。

const_iterator upper_bound( 
   const Key& _Key 
) const; 

iterator upper_bound( 
   const Key& _Key 
);

参数

_Key
参数用键元素的排序关键字进行比较从搜索集的。

返回值

解决一元素定位在集合与键与键的 迭代器 或 const_iterator 参数大于或成功解决上元素的位置集，如果与对于找到键。

示例

// set_upper_bound.cpp
// compile with: /EHsc
#include <set>
#include <iostream>

int main( )
{
   using namespace std;   
   set <int> s1;
   set <int> :: const_iterator s1_AcIter, s1_RcIter;
   
   s1.insert( 10 );
   s1.insert( 20 );
   s1.insert( 30 );

   s1_RcIter = s1.upper_bound( 20 );
   cout << "The first element of set s1 with a key greater "
        << "than 20 is: " << *s1_RcIter << "." << endl;

   s1_RcIter = s1.upper_bound( 30 );

   // If no match is found for the key, end( ) is returned
   if ( s1_RcIter == s1.end( ) )
      cout << "The set s1 doesn't have an element "
           << "with a key greater than 30." << endl;
   else
      cout << "The element of set s1 with a key > 40 is: "
           << *s1_RcIter << "." << endl;

   // The element at a specific location in the set can be found 
   // by using a dereferenced iterator addressing the location
   s1_AcIter = s1.begin( );
   s1_RcIter = s1.upper_bound( *s1_AcIter );
   cout << "The first element of s1 with a key greater than"
        << endl << "that of the initial element of s1 is: "
        << *s1_RcIter << "." << endl;
}