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<H2>upper_bound()</H2>
<P><B>Library:</B>&nbsp;&nbsp;<A HREF="2-9.html">Algorithms</A></P>
<PRE><HR><B><I>Function</I></B><HR></PRE>
<UL>
<LI><A HREF="#sec1">Local Index</A></LI>
<LI><A HREF="#sec2">Summary</A></LI>
<LI><A HREF="#sec3">Synopsis</A></LI>
<LI><A HREF="#sec4">Description</A></LI>
<LI><A HREF="#sec5">Complexity</A></LI>
<LI><A HREF="#sec6">Example</A></LI>
<LI><A HREF="#sec7">See Also</A></LI>
<LI><A HREF="#sec8">Standards Conformance</A></LI>
</UL>
<A NAME="sec1"><H3>Local Index</H3></A>
No Entries
<A NAME="sec2"><H3>Summary</H3></A>
<P>An algorithm that determines the last valid position for a value in a sorted container</P>
<A NAME="sec3"><H3>Synopsis</H3></A>
<PRE>#include &lt;algorithm&gt;
namespace std {
template &lt;class ForwardIterator, class T&gt;
ForwardIterator
upper_bound(ForwardIterator start, ForwardIterator finish,
const T&amp; value);
template &lt;class ForwardIterator, class T, class Compare&gt;
ForwardIterator
upper_bound(ForwardIterator start, ForwardIterator finish,
const T&amp; value, Compare comp);
}
</PRE>
<A NAME="sec4"><H3>Description</H3></A>
<P>The <SAMP>upper_bound()</SAMP> algorithm is one of a set of binary search algorithms. All of these algorithms perform binary searches on ordered sequences. Each algorithm has two versions. The first version uses <SAMP>operator&lt;()</SAMP> to perform the comparison, and assumes that the sequence has been sorted using that operator. The second version allows you to include a function object of type <SAMP>Compare</SAMP>, and assumes that <SAMP>Compare</SAMP> is the function used to sort the sequence. The function object must be a binary predicate. </P>
<P>The <SAMP>upper_bound()</SAMP> algorithm finds the last position in a sequence that <SAMP>value</SAMP> can occupy without violating the sequence's ordering. <SAMP>upper_bound()</SAMP>'s return value is the iterator for the first element in the sequence that is greater than <SAMP>value</SAMP>, or, when the comparison operator is used, the first element that does NOT satisfy the comparison function. Because the algorithm is restricted to using the less than operator or the user-defined function to perform the search, <SAMP>upper_bound()</SAMP> returns an iterator <SAMP>i</SAMP> in the range <SAMP>[start, finish)</SAMP> such that for any iterator <SAMP>j</SAMP> in the range <SAMP>[start, i)</SAMP> the appropriate version of the following conditions holds:</P>
<P><SAMP>!(value &lt; *j)</SAMP></P>
<P>or </P>
<P><SAMP>comp(value, *j) == false</SAMP></P>
<A NAME="sec5"><H3>Complexity</H3></A>
<P><SAMP>upper_bound()</SAMP> performs at most <SAMP>log(finish - start) + 1</SAMP> comparisons.</P>
<A NAME="sec6"><H3>Example</H3></A>
<UL><PRE>//
// ul_bound.cpp
//
#include &lt;vector&gt;
#include &lt;algorithm&gt;
#include &lt;functional&gt;
#include &lt;iostream&gt;
int main ()
{
typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; Vector;
typedef Vector::const_iterator Iterator;
const int a[] = { 0, 1, 2, 2, 3, 4, 5, 5, 5, 6, 7 };
// Set up a vector.
const Vector v (a, a + sizeof a / sizeof *a);
// Try lower_bound variants.
Iterator it1 = std::lower_bound (v.begin (),v.end (), 3);
Iterator it2 = std::lower_bound (v.begin (),v.end (), 2,
std::less&lt;int&gt;());
// Try upper_bound variants.
Iterator it3 = std::upper_bound (v.begin (), v.end (), 3);
Iterator it4 = std::upper_bound (v.begin (), v.end (), 2,
std::less&lt;int&gt;());
std::cout &lt;&lt; "\n\nThe upper and lower bounds of 3: ( "
&lt;&lt; *it1 &lt;&lt; " , " &lt;&lt; *it3
&lt;&lt; " ]\n\n\nThe upper and lower bounds of 2: ( "
&lt;&lt; *it2 &lt;&lt; " , " &lt;&lt; *it4 &lt;&lt; " ]\n";
return 0;
}
Program Output:
</PRE></UL>
<UL><PRE>
The upper and lower bounds of 3: ( 3 , 4 ]
The upper and lower bounds of 2: ( 2 , 3 ]
</PRE></UL>
<A NAME="sec7"><H3>See Also</H3></A>
<P><SAMP><A HREF="lower-bound.html">lower_bound()</A></SAMP>, <SAMP><A HREF="equal-range.html">equal_range()</A></SAMP></P>
<A NAME="sec8"><H3>Standards Conformance</H3></A>
<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.3.3.2</I></P>
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