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 <H2>find_first_of()</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>Algorithm that finds the first occurrence of any value from one sequence in another sequence</P>
 <A NAME="sec3"><H3>Synopsis</H3></A>

 <PRE>#include &lt;algorithm&gt;

 namespace std {
   template &lt;class ForwardIterator1, class ForwardIterator2&gt;
   ForwardIterator1 find_first_of (ForwardIterator1 start1,
                                   ForwardIterator1 finish1,
                                   ForwardIterator2 start2,
                                   ForwardIterator2 finish2);

   template &lt;class ForwardIterator1, class ForwardIterator2,
             class BinaryPredicate&gt;
   ForwardIterator1 find_first_of (ForwardIterator1 start1,
                                   ForwardIterator1 finish1,
                                   ForwardIterator2 start2,
                                   ForwardIterator2 finish2,
                                   BinaryPredicate binary_pred);
 }
 </PRE>
 <A NAME="sec4"><H3>Description</H3></A>
 <P>The <SAMP>find_first_of()</SAMP> algorithm finds the first occurrence of a value from a sequence, specified by <SAMP>start2, finish2</SAMP>, in a sequence specified by <SAMP>start1, finish1</SAMP>. The algorithm returns an iterator in the range <SAMP>[start1, finish1) </SAMP>that points to the first matching element<SAMP>.</SAMP> If the first sequence <SAMP>[start1, finish1)</SAMP> does not contain any of the values in the second sequence, <SAMP>find_first_of()</SAMP> returns <SAMP>finish1</SAMP>. </P>
 <P>In other words, <SAMP>find_first_of()</SAMP> returns the first iterator <SAMP>i</SAMP> in <SAMP>[start1, finish1)</SAMP>such that for some iterator <SAMP>j</SAMP> in the range <SAMP>[start2, finish2)</SAMP>, the following conditions hold: </P>

 <UL><PRE>*i == *j, binary_pred(*i,*j) == true.
 </PRE></UL>
 <P>Or <SAMP>find_first_of()</SAMP> returns <SAMP>finish1</SAMP> if no such iterator is found.</P>
 <P>Two versions of the algorithm exist. The first uses the equality operator as the default binary predicate, and the second allows you to specify a binary predicate.</P>
 <A NAME="sec5"><H3>Complexity</H3></A>
 <P>At most <SAMP>(finish1 - start1)*(finish2 - start2)</SAMP> applications of the corresponding predicate are done.</P>
 <A NAME="sec6"><H3>Example</H3></A>

 <UL><PRE>//
 // find_f_o.cpp
 //

 #include &lt;algorithm&gt;    // for find_first_of
 #include &lt;functional&gt;   // for equal_to
 #include &lt;iostream&gt;     // for cout, endl
 #include &lt;vector&gt;       // for vector


 int main ()
 {
     // Typedef for convenience.
     typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; vector;

     const vector::value_type a1[] = {
         0, 1, 2, 2, 3, 4, 2, 2, 6, 7
     };
     const vector::value_type a2[] = { 6, 4 };

     // Set up two vectors.
     const vector v1(a1, a1 + sizeof a1 / sizeof *a1);
     const vector v2(a2, a2 + sizeof a2 / sizeof *a2);

     // Try both find_first_of variants.
     vector::const_iterator it1 =
         std::find_first_of(v1.begin(), v1.end(),
                            v2.begin(), v2.end());

     vector::const_iterator it2 =
         std::find_first_of(v1.begin(), v1.end(),
                            v2.begin(), v2.end(),
                         std::equal_to&lt;vector::value_type&gt;());

     // Create an output stream iterator.
     std::ostream_iterator&lt;vector::value_type, char,
         std::char_traits&lt;char&gt; &gt; out(std::cout, " " );

     // Output results.
     std::cout &lt;&lt; "For the vectors { ";
     std::copy(v1.begin(), v1.end(), out);

     std:: cout &lt;&lt; "} and { ";
     std::copy(v2.begin(), v2.end(), out);

     std::cout &lt;&lt; "}\nboth versions of find_first_of "
               &lt;&lt; "point to: " &lt;&lt; *it1 &lt;&lt; std::endl;

     // Return 0 on success, non-0 on failure.
     return !(*it1 == *it2);
 }


 Program Output
 </PRE></UL>
 <UL><PRE>For the vectors { 0 1 2 2 3 4 2 2 6 7 } and { 6 4 }
 both versions of find_first_of point to: 4
 </PRE></UL>
 <A NAME="sec7"><H3>See Also</H3></A>
 <P><A HREF="algorithms.html">Algorithms</A>, <SAMP><A HREF="adjacent-find.html">adjacent_find()</A></SAMP>, <SAMP><A HREF="find.html">find()</A></SAMP>, <SAMP><A HREF="find-if.html">find_if()</A></SAMP>, <SAMP><A HREF="find-end.html">find_end()</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 25.1.4</I></P>

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	<H2>find_first_of()</H2>
	<P><B>Library:</B>  <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>Algorithm that finds the first occurrence of any value from one sequence in another sequence</P>
	<A NAME="sec3"><H3>Synopsis</H3></A>

	<PRE>#include <algorithm>

	namespace std {
	template <class ForwardIterator1, class ForwardIterator2>
	ForwardIterator1 find_first_of (ForwardIterator1 start1,
	ForwardIterator1 finish1,
	ForwardIterator2 start2,
	ForwardIterator2 finish2);

	template <class ForwardIterator1, class ForwardIterator2,
	class BinaryPredicate>
	ForwardIterator1 find_first_of (ForwardIterator1 start1,
	ForwardIterator1 finish1,
	ForwardIterator2 start2,
	ForwardIterator2 finish2,
	BinaryPredicate binary_pred);
	}
	</PRE>
	<A NAME="sec4"><H3>Description</H3></A>
	<P>The <SAMP>find_first_of()</SAMP> algorithm finds the first occurrence of a value from a sequence, specified by <SAMP>start2, finish2</SAMP>, in a sequence specified by <SAMP>start1, finish1</SAMP>. The algorithm returns an iterator in the range <SAMP>[start1, finish1) </SAMP>that points to the first matching element<SAMP>.</SAMP> If the first sequence <SAMP>[start1, finish1)</SAMP> does not contain any of the values in the second sequence, <SAMP>find_first_of()</SAMP> returns <SAMP>finish1</SAMP>. </P>
	<P>In other words, <SAMP>find_first_of()</SAMP> returns the first iterator <SAMP>i</SAMP> in <SAMP>[start1, finish1)</SAMP>such that for some iterator <SAMP>j</SAMP> in the range <SAMP>[start2, finish2)</SAMP>, the following conditions hold: </P>

	<UL><PRE>i == j, binary_pred(i,j) == true.
	</PRE></UL>
	<P>Or <SAMP>find_first_of()</SAMP> returns <SAMP>finish1</SAMP> if no such iterator is found.</P>
	<P>Two versions of the algorithm exist. The first uses the equality operator as the default binary predicate, and the second allows you to specify a binary predicate.</P>
	<A NAME="sec5"><H3>Complexity</H3></A>
	<P>At most <SAMP>(finish1 - start1)*(finish2 - start2)</SAMP> applications of the corresponding predicate are done.</P>
	<A NAME="sec6"><H3>Example</H3></A>

	<UL><PRE>//
	// find_f_o.cpp
	//

	#include <algorithm> // for find_first_of
	#include <functional> // for equal_to
	#include <iostream> // for cout, endl
	#include <vector> // for vector


	int main ()
	{
	// Typedef for convenience.
	typedef std::vector<int, std::allocator<int> > vector;

	const vector::value_type a1[] = {
	0, 1, 2, 2, 3, 4, 2, 2, 6, 7
	};
	const vector::value_type a2[] = { 6, 4 };

	// Set up two vectors.
	const vector v1(a1, a1 + sizeof a1 / sizeof *a1);
	const vector v2(a2, a2 + sizeof a2 / sizeof *a2);

	// Try both find_first_of variants.
	vector::const_iterator it1 =
	std::find_first_of(v1.begin(), v1.end(),
	v2.begin(), v2.end());

	vector::const_iterator it2 =
	std::find_first_of(v1.begin(), v1.end(),
	v2.begin(), v2.end(),
	std::equal_to<vector::value_type>());

	// Create an output stream iterator.
	std::ostream_iterator<vector::value_type, char,
	std::char_traits<char> > out(std::cout, " " );

	// Output results.
	std::cout << "For the vectors { ";
	std::copy(v1.begin(), v1.end(), out);

	std:: cout << "} and { ";
	std::copy(v2.begin(), v2.end(), out);

	std::cout << "}\nboth versions of find_first_of "
	<< "point to: " << *it1 << std::endl;

	// Return 0 on success, non-0 on failure.
	return !(it1 == it2);
	}


	Program Output
	</PRE></UL>
	<UL><PRE>For the vectors { 0 1 2 2 3 4 2 2 6 7 } and { 6 4 }
	both versions of find_first_of point to: 4
	</PRE></UL>
	<A NAME="sec7"><H3>See Also</H3></A>
	<P><A HREF="algorithms.html">Algorithms</A>, <SAMP><A HREF="adjacent-find.html">adjacent_find()</A></SAMP>, <SAMP><A HREF="find.html">find()</A></SAMP>, <SAMP><A HREF="find-if.html">find_if()</A></SAMP>, <SAMP><A HREF="find-end.html">find_end()</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 25.1.4</I></P>

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