📄 uninitialized_fill_n.html

📁 VC书籍介绍C++的应用的TheOODesignProcess.zip 电子书好用的
💻 HTML
字号:
<HTML>
<HEAD>
   <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
   <META NAME="Author" CONTENT="Zafir Anjum">
   <TITLE>MFC Programmer's SourceBook : STL Programmer's Guide</TITLE>
    <META name="description" 
     content="A freely available implementation 
     of the C++ Standard Template Library, including 
     hypertext documentation.">
	<META name="keywords" 
	content="generic programming, STL, standard template library">
</HEAD>

<SCRIPT LANGUAGE="JavaScript"><!--
var adcategory = "cpp";
// -->
</SCRIPT>
<body background="../../fancyhome/back.gif" bgcolor="#FFFFFF" >
<SCRIPT LANGUAGE="JavaScript"><!--
var nfrm = location.href.indexOf("_nfrm_");
var validframes = (top.frames.length > 0 && top.frames['ad'] && top.frames['logo'] );
var random = Math.random();

if( !validframes && nfrm == -1 )
{
	var dclkPage = "www.codeguru.com/";
	if( self.adcategory )
		dclkPage += adcategory;
	else
		dclkPage += "mfc";
	document.write('<nolayer><center>');
	document.write('<iframe src="http://ad.doubleclick.net/adi/' + dclkPage + ';ord='
	 + random + '" width=470 height=62 marginwidth=0 marginheight=0 hspace=0 vspace=0 '
	 + 'frameborder=0 scrolling=no bordercolor="#000000">');
	document.write('<a href="http://ad.doubleclick.net/jump/' + dclkPage + ';ord='
	 + random + '">');
	document.write('<img src="http://ad.doubleclick.net/ad/' + dclkPage + ';ord='
	 + random + '" height=60 width=468>' + '</a>');
	document.write('</iframe>');
	document.write('</center></nolayer>');
	document.write('<layer  src="http://ad.doubleclick.net/adl/' + dclkPage + 
	 ';ord=' + random + '"></layer>');
	document.write('<ilayer visibility=hide width=468 height=83></ilayer>');
}


//		top.location = "/show.cgi?" + adcategory + "=" + location.pathname;


// -->
</SCRIPT>
<noscript>
<p align="center">
<a href="http://ad.doubleclick.net/jump/www.codeguru.com/cpp;ord=NupcAdFCY34AAHq0QbQ">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupcAdFCY34AAHq0QbQ"></a>
</p>
</noscript>





<BR Clear>
<H1>uninitialized_fill_n</H1>

<Table CellPadding=0 CellSpacing=0 width=100%>
<TR>
<TD Align=left><Img src = "allocators.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><Img src = "algorithms.gif" Alt=""   WIDTH = "194"  HEIGHT = "38" ></TD>
<TD Align=right></TD>
</TR>
<TR>
<TD Align=left VAlign=top><b>Categories</b>: allocators, algorithms</TD>
<TD Align=right VAlign=top><b>Component type</b>: function</TD>
</TR>
</Table>

<h3>Prototype</h3>
<pre>
template &lt;class ForwardIterator, class Size, class T&gt;
ForwardIterator uninitialized_fill_n(ForwardIterator first, Size n,
                                     const T&amp; x);
</pre>                   
<h3>Description</h3>
In C++, the operator <tt>new</tt> allocates memory for an object and then
creates an object at that location by calling a constructor.  Occasionally,
however, it is useful to separate those two operations. <A href="#1">[1]</A> If each iterator
in the range <tt>[first, first + n)</tt> points to uninitialized
memory, then <tt>uninitialized_fill_n</tt> creates copies of <tt>x</tt>
in that range.  That is, for each iterator <tt>i</tt> in the range <tt>[first,
first + n)</tt>, <tt>uninitialized_fill_n</tt> creates a copy of <tt>x</tt> in 
the location pointed to <tt>i</tt> by calling <tt><A href="construct.html">construct</A>(&amp;*i, x)</tt>.
<h3>Definition</h3>
Defined in <A href="algo.h">algo.h</A>.  The implementation is in <A href="algobase.h" tppabs="http://www.sgi.com/Technology/STL/algobase.h">algobase.h</A>.
<h3>Requirements on types</h3>
<UL>
<LI>
<tt>ForwardIterator</tt> is a model of <A href="ForwardIterator.html">Forward Iterator</A>.
<LI>
<tt>ForwardIterator</tt> is mutable.
<LI>
<tt>Size</tt> is an integral type that is convertible to <tt>ForwardIterator</tt>'s
   distance type.
<LI>
<tt>ForwardIterator</tt>'s value type has a constructor that takes a
   single argument of type <tt>T</tt>.
</UL>
<h3>Preconditions</h3>
<UL>
<LI>
<tt>n</tt> is nonnegative.
<LI>
<tt>[first, first + n)</tt> is a valid range.
<LI>
Each iterator in <tt>[first, first + n)</tt> points to
   a region of uninitialized memory that is large enough to store
   a value of <tt>ForwardIterator</tt>'s value type.
</UL>
<h3>Complexity</h3>
Linear.  Exactly <tt>n</tt> constructor calls.
<h3>Example</h3>
<pre>
class Int {
public:
  Int(int x) : val(x) {}
  int get() { return val; }
private:
  int val;
};    

int main()
{
  const int N = 137;
  
  Int val(46);
  Int* A = (Int*) malloc(N * sizeof(Int));
  uninitialized_fill_n(A, N, val);
}
</pre>
<h3>Notes</h3>
<P><A name="1">[1]</A>
In particular, this sort of low-level memory management is used
in the implementation of some container classes.
<h3>See also</h3>
<A href="Allocators.html">Allocators</A>, <tt><A href="construct.html" tppabs="http://www.sgi.com/Technology/STL/construct.shtml">construct</A></tt>, <tt><A href="destroy.html" tppabs="http://www.sgi.com/Technology/STL/destroy.shtml">destroy</A></tt>, 
<tt><A href="uninitialized_copy.html">uninitialized_copy</A></tt>, <tt><A href="uninitialized_fill.html" tppabs="http://www.sgi.com/Technology/STL/uninitialized_fill.shtml">uninitialized_fill</A></tt>,
<tt><A href="raw_storage_iterator.html">raw_storage_iterator</A></tt>

<HR SIZE="6"> <FONT SIZE="-2"> Copyright &copy; 1996 Silicon Graphics, Inc.
<HR>
<TABLE BORDER=0 WIDTH="100%" >
<TR>
<TD WIDTH="33%"><FONT SIZE=-1><A HREF="index.html" >
STL</A></FONT></TD>

<TD WIDTH="33%">
<CENTER><FONT SIZE=-2>&copy; Copyright 1997-1998 CodeGuru</FONT>&nbsp;</CENTER>
</TD>

<TD WIDTH="34%">
<DIV ALIGN=right><FONT SIZE=-1>Contact : <A HREF="mailto:webmaster@codeguru.com">webmaster@codeguru.com</A>&nbsp;</FONT></DIV>
</TD>
</TR>
</TABLE>
<SCRIPT LANGUAGE="JavaScript" ><!--
var adurl = "/cgi-bin/doubleclick.cgi?";

if( self.adcategory )
	adurl += adcategory;
else
	adurl += "mfc";

if( self.parent.norefreshad )
	parent.norefreshad = false;
else if( validframes )
	parent.frames['ad'].location = adurl;



if( !validframes && nfrm == -1)
{
	var dclkPage = "www.codeguru.com/";
	if( self.adcategory )
		dclkPage += adcategory;
	else 
		dclkPage += "mfc";
//	var random = Math.random();
	document.write('<nolayer><center>');
	document.write('<iframe src="http://ad.doubleclick.net/adi/' + dclkPage + ';ord='
	 + random + '" width=470 height=62 marginwidth=0 marginheight=0 hspace=0 vspace=0 '
	 + 'frameborder=0 scrolling=no bordercolor="#000000">');
	document.write('<a href="http://ad.doubleclick.net/jump/' + dclkPage + ';ord='
	 + random + '">');
	document.write('<img src="http://ad.doubleclick.net/ad/' + dclkPage + ';ord='
	 + random + '" height=60 width=468>' + '</a>');
	document.write('</iframe>');
	document.write('</center></nolayer>');
	document.write('<layer  src="http://ad.doubleclick.net/adl/' + dclkPage + 
	 ';ord=' + random + '"></layer>');
	document.write('<ilayer visibility=hide width=468 height=83></ilayer>');
}

// -->
</SCRIPT> 
<!-- SCRIPT LANGUAGE="JavaScript" SRC="/global/fscript.js">
//
</SCRIPT --> 

<noscript>
<p align="center">
<a href="http://ad.doubleclick.net/jump/www.codeguru.com/cpp;ord=NupcAdFCY34AAHq0QbQ">
<img src="http://ad.doubleclick.net/ad/www.codeguru.com/cpp;ord=NupcAdFCY34AAHq0QbQ"></a>
</p>
</noscript>





</BODY>
</HTML>
💿 文件大小 718 K
👤 上传用户 wangshengzaishi
📂 所属分类 VC书籍
🏷️ 相关标签

#TheOODesignProcess #zip #书籍 #电子书
⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -