📄 raw_storage_iterator.html
字号:
<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. Hewlett-Packard Company makes no -- representations about the suitability of this software for any -- purpose. It is provided "as is" without express or implied warranty. -- --><Head><Title>raw_storage_iterator<ForwardIterator, T></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>raw_storage_iterator<ForwardIterator, T></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 = "type.gif" Alt="" WIDTH = "194" HEIGHT = "39" ></TD></TR><TR><TD Align=left><Img src = "iterators.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD><TD Align=right></TD></TR><TR><TD Align=left><Img src = "adaptors.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD><TD Align=right></TD></TR><TR><TD Align=left VAlign=top><b>Categories</b>: allocators, iterators, adaptors</TD><TD Align=right VAlign=top><b>Component type</b>: type</TD></TR></Table><h3>Description</h3>In C++, the operator <tt>new</tt> allocates memory for an object and thencreates 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 <tt>i</tt> is aniterator that points to a region of uninitialized memory, then youcan use <tt><A href="construct.html">construct</A></tt> to create an object in the location pointed toby <tt>i</tt>. <tt>Raw_storage_iterator</tt> is an adaptor that makes thisprocedure more convenient. If <tt>r</tt> is a <tt>raw_storage_iterator</tt>, thenit has some underlying iterator <tt>i</tt>. The expression <tt>*r = x</tt> isequivalent to <tt><A href="construct.html">construct</A>(&*i, x)</tt>.<h3>Example</h3><pre>class Int {public: Int(int x) : val(x) {} int get() { return val; }private: int val;}; int main(){ int A1[] = {1, 2, 3, 4, 5, 6, 7}; const int N = sizeof(A1) / sizeof(int); Int* A2 = (Int*) malloc(N * sizeof(Int)); <A href="transform.html">transform</A>(A1, A1 + N, raw_storage_iterator<Int*, int>(A2), <A href="negate.html">negate</A><int>());}</pre><h3>Definition</h3>Defined in the standard header <A href="memory">memory</A>, and in the nonstandardbackward-compatibility header <A href="iterator.h">iterator.h</A>.<h3>Template parameters</h3><Table border><TR><TH>Parameter</TH><TH>Description</TH><TH>Default</TH></TR><TR><TD VAlign=top>OutputIterator</TD><TD VAlign=top>The type of the <tt>raw_storage_iterator</tt>'s underlying iterator.</TD><TD VAlign=top> </TD></TR><TR><TD VAlign=top><tt>T</tt></TD><TD VAlign=top>The type that will be used as the argument to the constructor.</TD><TD VAlign=top> </TD></tr></table><h3>Model of</h3><A href="OutputIterator.html">Output Iterator</A><h3>Type requirements</h3><UL><LI><tt>ForwardIterator</tt> is a model of <A href="ForwardIterator.html">Forward Iterator</A><LI><tt>ForwardIterator</tt>'s value type has a constructor that takes a single argument of type <tt>T</tt>.</UL><h3>Public base classes</h3>None.<h3>Members</h3><Table border><TR><TH>Member</TH><TH>Where defined</TH><TH>Description</TH></TR><TR><TD VAlign=top><tt>raw_storage_iterator(ForwardIterator x)</tt></TD><TD VAlign=top><tt>raw_storage_iterator</tt></TD><TD VAlign=top>See below.</TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator(const raw_storage_iterator&)</tt></TD><TD VAlign=top> <A href="trivial.html">trivial iterator</A></TD><TD VAlign=top>The copy constructor</TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator=(const raw_storage_iterator&)</tt></TD><TD VAlign=top> <A href="trivial.html">trivial iterator</A></TD><TD VAlign=top>The assignment operator</TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator*()</tt></TD><TD VAlign=top> <A href="OutputIterator.html">Output Iterator</A></TD><TD VAlign=top>Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#2">[2]</A></TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator=(const Sequence::value_type&)</tt></TD><TD VAlign=top> <A href="OutputIterator.html">Output Iterator</A></TD><TD VAlign=top>Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#2">[2]</A></TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator++()</tt></TD><TD VAlign=top> <A href="OutputIterator.html">Output Iterator</A></TD><TD VAlign=top>Preincrement.</TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator++(int)</tt></TD><TD VAlign=top> <A href="OutputIterator.html">Output Iterator</A></TD><TD VAlign=top>Postincrement.</TD></TR><TR><TD VAlign=top><tt>output_iterator_tag iterator_category(const raw_storage_iterator&)</tt></TD><TD VAlign=top> <A href="iterator_tags.html">iterator tags</A></TD><TD VAlign=top>Returns the iterator's category. This is a global function, not a member.</TD></tr></table><h3>New members</h3>These members are not defined in the <A href="OutputIterator.html">Output Iterator</A> requirements,but are specific to <tt>raw_storage_iterator</tt>.<Table border><TR><TH>Function</TH><TH>Description</TH></TR><TR><TD VAlign=top><tt>raw_storage_iterator(ForwardIterator i)</tt></TD><TD VAlign=top>Creates a <tt>raw_storage_iterator</tt> whose underlying iterator is <tt>i</tt>.</TD></TR><TR><TD VAlign=top><tt>raw_storage_iterator& operator=(const T& val)</tt></TD><TD VAlign=top>Constructs an object of <tt>ForwardIterator</tt>'s value type at the location pointed to by the iterator, using <tt>val</tt> as the constructor's argument.</TD></tr></table><h3>Notes</h3><P><A name="1">[1]</A>In particular, this sort of low-level memory management is usedin the implementation of some container classes.<P><A name="2">[2]</A>Note how assignment through a <tt>raw_storage_iterator</tt> is implemented.In general, unary <tt>operator*</tt> must be defined so that it returns aproxy object, where the proxy object defines <tt>operator=</tt> to performthe insert operation. In this case, for the sake of simplicity, theproxy object is the <tt>raw_storage_iterator</tt> itself. That is, <tt>*i</tt> returns <tt>i</tt>, and <tt>*i = t</tt> is equivalent to <tt>i = t</tt>. You should not,however, rely on this behavior. It is an implementation detail,and it is not guaranteed to remain the same in future versions.<h3>See also</h3><A href="Allocators.html">Allocators</A>, <tt><A href="construct.html">construct</A></tt>, <tt><A href="destroy.html">destroy</A></tt>, <tt><A href="uninitialized_copy.html">uninitialized_copy</A></tt><tt><A href="uninitialized_fill.html">uninitialized_fill</A></tt>, <tt><A href="uninitialized_fill_n.html">uninitialized_fill_n</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
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 + -