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<HTML><!-- -- Copyright (c) 1996-1999 -- Silicon Graphics Computer Systems, Inc. -- -- Permission to use, copy, modify, distribute and sell this software -- and its documentation for any purpose is hereby granted without fee, -- provided that the above copyright notice appears in all copies and -- that both that copyright notice and this permission notice appear -- in supporting documentation. Silicon Graphics makes no -- representations about the suitability of this software for any -- purpose. It is provided "as is" without express or implied warranty. -- -- Copyright (c) 1994 -- Hewlett-Packard Company -- -- Permission to use, copy, modify, distribute and sell this software -- and its documentation for any purpose is hereby granted without fee, -- provided that the above copyright notice appears in all copies and -- that both that copyright notice and this permission notice appear -- in supporting documentation. 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It is provided "as is" without express or implied warranty. -- --><Head><Title>includes</Title><!-- Generated by htmldoc --></HEAD><BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b" ALINK="#ff0000"> <IMG SRC="CorpID.gif" ALT="SGI" HEIGHT="43" WIDTH="151"> <!--end header--><BR Clear><H1>includes</H1><Table CellPadding=0 CellSpacing=0 width=100%><TR><TD Align=left><Img src = "algorithms.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD><TD Align=right><Img src = "function.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD></TR><TR><TD Align=left VAlign=top><b>Category</b>: algorithms</TD><TD Align=right VAlign=top><b>Component type</b>: function</TD></TR></Table><h3>Prototype</h3><tt>Includes</tt> is an overloaded name; there are actually two <tt>includes</tt>functions.<pre>template <class <A href="InputIterator.html">InputIterator</A>1, class <A href="InputIterator.html">InputIterator</A>2>bool includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);template <class <A href="InputIterator.html">InputIterator</A>1, class <A href="InputIterator.html">InputIterator</A>2, class <A href="StrictWeakOrdering.html">StrictWeakOrdering</A>>bool includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, StrictWeakOrdering comp);</pre> <h3>Description</h3><tt>Includes</tt> tests whether one sorted range includes another sortedrange. That is, it returns <tt>true</tt> if and only if, for every element in<tt>[first2, last2)</tt>, an equivalent element <A href="#1">[1]</A> is also present in<tt>[first1, last1)</tt> <A href="#2">[2]</A>.Both <tt>[first1, last1)</tt> and <tt>[first2, last2)</tt> must be sorted in ascending order.<P>The two versions of <tt>includes</tt> differ in how they define whether oneelement is less than another. The first version comparesobjects using <tt>operator<</tt>, and the second compares objects usingthe <A href="functors.html">function object</A> <tt>comp</tt>.<h3>Definition</h3>Defined in the standard header <A href="algorithm">algorithm</A>, and in the nonstandardbackward-compatibility header <A href="algo.h">algo.h</A>.<h3>Requirements on types</h3>For the first version:<UL><LI><tt>InputIterator1</tt> is a model of <A href="InputIterator.html">Input Iterator</A>.<LI><tt>InputIterator2</tt> is a model of <A href="InputIterator.html">Input Iterator</A>.<LI><tt>InputIterator1</tt> and <tt>InputIterator2</tt> have the same value type.<LI><tt>InputIterator</tt>'s value type is a model of <A href="LessThanComparable.html">LessThan Comparable</A>.<LI>The ordering on objects of <tt>InputIterator1</tt>'s value type is a <i>strict weak ordering</i>, as defined in the <A href="LessThanComparable.html">LessThan Comparable</A> requirements.</UL>For the second version:<UL><LI><tt>InputIterator1</tt> is a model of <A href="InputIterator.html">Input Iterator</A>.<LI><tt>InputIterator2</tt> is a model of <A href="InputIterator.html">Input Iterator</A>.<LI><tt>InputIterator1</tt> and <tt>InputIterator2</tt> have the same value type.<LI><tt>StrictWeakOrdering</tt> is a model of <A href="StrictWeakOrdering.html">Strict Weak Ordering</A>.<LI><tt>InputIterator1</tt>'s value type is convertible to <tt>StrictWeakOrdering</tt>'s argument type.</UL><h3>Preconditions</h3>For the first version:<UL><LI><tt>[first1, last1)</tt> is a valid range.<LI><tt>[first2, last2)</tt> is a valid range.<LI><tt>[first1, last1)</tt> is ordered in ascending order according to <tt>operator<</tt>. That is, for every pair of iterators <tt>i</tt> and <tt>j</tt> in <tt>[first1, last1)</tt> such that <tt>i</tt> precedes <tt>j</tt>, <tt>*j < *i</tt> is <tt>false</tt>.<LI><tt>[first2, last2)</tt> is ordered in ascending order according to <tt>operator<</tt>. That is, for every pair of iterators <tt>i</tt> and <tt>j</tt> in <tt>[first2, last2)</tt> such that <tt>i</tt> precedes <tt>j</tt>, <tt>*j < *i</tt> is <tt>false</tt>.</UL>For the second version:<UL><LI><tt>[first1, last1)</tt> is a valid range.<LI><tt>[first2, last2)</tt> is a valid range.<LI><tt>[first1, last1)</tt> is ordered in ascending order according to <tt>comp</tt>. That is, for every pair of iterators <tt>i</tt> and <tt>j</tt> in <tt>[first1, last1)</tt> such that <tt>i</tt> precedes <tt>j</tt>, <tt>comp(*j, *i)</tt> is <tt>false</tt>.<LI><tt>[first2, last2)</tt> is ordered in ascending order according to <tt>comp</tt>. That is, for every pair of iterators <tt>i</tt> and <tt>j</tt> in <tt>[first2, last2)</tt> such that <tt>i</tt> precedes <tt>j</tt>, <tt>comp(*j, *i)</tt> is <tt>false</tt>.</UL><h3>Complexity</h3>Linear. Zero comparisons if either <tt>[first1, last1)</tt> or <tt>[first2, last2)</tt>is an empty range, otherwise at most <tt>2 * ((last1 - first1) + (last2 -first2)) - 1</tt> comparisons.<h3>Example</h3><pre>int A1[] = { 1, 2, 3, 4, 5, 6, 7 };int A2[] = { 1, 4, 7 };int A3[] = { 2, 7, 9 };int A4[] = { 1, 1, 2, 3, 5, 8, 13, 21 };int A5[] = { 1, 2, 13, 13 };int A6[] = { 1, 1, 3, 21 };const int N1 = sizeof(A1) / sizeof(int);const int N2 = sizeof(A2) / sizeof(int);const int N3 = sizeof(A3) / sizeof(int);const int N4 = sizeof(A4) / sizeof(int);const int N5 = sizeof(A5) / sizeof(int);const int N6 = sizeof(A6) / sizeof(int);cout << "A2 contained in A1: " << (includes(A1, A1 + N1, A2, A2 + N2) ? "true" : "false") << endl;cout << "A3 contained in A1: " << (includes(A1, A1 + N2, A3, A3 + N3) ? "true" : "false") << endl;cout << "A5 contained in A4: " << (includes(A4, A4 + N4, A5, A5 + N5) ? "true" : "false") << endl;cout << "A6 contained in A4: " << (includes(A4, A4 + N4, A6, A6 + N6) ? "true" : "false") << endl;</pre>The output is:<pre>A2 contained in A1: trueA3 contained in A1: falseA5 contained in A4: falseA6 contained in A4: true</pre><h3>Notes</h3><P><A name="1">[1]</A>This reads "an equivalent element" rather than "the same element"because the ordering by which the input ranges are sortedis permitted to be a strict weak ordering that is not a total ordering:there might be values <tt>x</tt> and <tt>y</tt> that areequivalent (that is, neither <tt>x < y</tt> nor <tt>y < x</tt> is true) but notequal. See the <A href="LessThanComparable.html">LessThan Comparable</A> requirements for a fullerdiscussion.) If you're using a total ordering(if you're using <tt>strcmp</tt>, for example, or if you're usingordinary arithmetic comparison on integers), then you can ignore thistechnical distinction: for a total ordering, equality and equivalenceare the same.<P><A name="2">[2]</A>Note that the range <tt>[first2, last2)</tt> may contain a consecutive rangeof equivalent elements: there is no requirement that every element inthe range be unique. In this case, <tt>includes</tt> will return <tt>false</tt>unless, for every element in <tt>[first2, last2)</tt>, a distinct equivalentelement is also present in <tt>[first1, last1)</tt>. That is, if a certainvalue appears <tt>n</tt> times in <tt>[first2, last2)</tt> and <tt>m</tt> times in <tt>[first1, last1)</tt>, then <tt>includes</tt> will return <tt>false</tt> if <tt>m < n</tt>.<h3>See also</h3><tt><A href="set_union.html">set_union</A></tt>, <tt><A href="set_intersection.html">set_intersection</A></tt>, <tt><A href="set_difference.html">set_difference</A></tt>, <tt><A href="set_symmetric_difference.html">set_symmetric_difference</A></tt>, <tt><A href="sort.html">sort</A></tt><!--start footer--> <HR SIZE="6"><A href="http://www.sgi.com/"><IMG SRC="surf.gif" HEIGHT="54" WIDTH="54" ALT="[Silicon Surf]"></A><A HREF="index.html"><IMG SRC="stl_home.gif" HEIGHT="54" WIDTH="54" ALT="[STL Home]"></A><BR><FONT SIZE="-2"><A href="http://www.sgi.com/Misc/sgi_info.html" TARGET="_top">Copyright © 1999 Silicon Graphics, Inc.</A> All Rights Reserved.</FONT><FONT SIZE="-3"><a href="http://www.sgi.com/Misc/external.list.html" TARGET="_top">TrademarkInformation</A></FONT><P></BODY></HTML> ⌨️ 快捷键说明
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