intro.htm

高效c++编程

<FONT ID="iititle"><A NAME="config"></A><A NAME="dingp42"></A>Setting Your Preferences</FONT><SCRIPT>create_link(42);</SCRIPT>

</P>

<P>
<A NAME="AUTO00035"></A><A NAME="dingp43"></A>
Call me an anarchist, but when it comes to accessing technical information, I just don't believe that one size fits all. Not one size window, not one size font, not one size image, not one size file. Your window system and browser let you control the window and font sizes you see, but to gain greater control over the appearance and behavior of the material on this CD, you'll need to take advantage of its configuration options.<SCRIPT>create_link(43);</SCRIPT>

</P>

<A NAME="AUTO00036"></A><A NAME="dingp44"></A><P>
The first thing you need to know is that each image on this CD is stored <I>five times</I>, each copy being a different size. As a general rule, the bigger the size of your screen and the higher the resolution of your graphics card, the larger the image you'll want to view. Of course, what really matters is what looks good to you. If you like tiny images on a big monitor, or if you prefer huge images on a small screen, you won't see me making a fuss. I'm the anarchist, remember? Furthermore, if your preference changes (at any time, for any reason), you can make an on-the-spot modification to how images are displayed. Your new preference will take effect immediately.<SCRIPT>create_link(44);</SCRIPT>

</P>
<A NAME="AUTO00037"></A><A NAME="dingp45"></A><P>
To change the size of images displayed in text (<I>i.e.</I>, outside the <A HREF="#navigation" onMouseOver = "self.status = 'Link to Navigation Area'; return true" onMouseOut = "self.status = self.defaultStatus">Navigation Area</A>), select a different icon in the &quot;Images&quot; portion of the Navigation Area. Try it now to see how the following diagram changes. (The diagram itself shows the hierarchy of diagnostics classes in the standard C++ library. You'll find this diagram in <SCRIPT>sendmetoo(49,8392,'E');</SCRIPT> onMouseOver = "self.status = 'Link to Item 49 of Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus">Item 49 of <I>Effective C++</I></A> and <SCRIPT>sendmetoo(12,76790,'M');</SCRIPT> onMouseOver = "self.status = 'Link to Item 12 of More Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus">Item 12 of <I>More Effective C++</I></A>.)<SCRIPT>create_link(45);</SCRIPT>

</P>

<A NAME="AUTO00038"></A>
<P>
<SPAN ID="Image1of1" STYLE="position: absolute; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE1.GIF" BORDER=0></SPAN>
<SPAN ID="Image1of2" STYLE="position: absolute; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE2.GIF" BORDER=0></SPAN>
<SPAN ID="Image1of3" STYLE="position: absolute; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE3.GIF" BORDER=0></SPAN>
<SPAN ID="Image1of4" STYLE="position: absolute; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE4.GIF" BORDER=0></SPAN>
<SPAN ID="Image1of5" STYLE="position: absolute; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE5.GIF" BORDER=0></SPAN>
<SPAN ID="Image1of6" STYLE="position: relative; z-index:1; visibility: hidden"><IMG SRC="./IMAGES/GRAPHICS/EXAMPLE5.GIF" BORDER=0></SPAN>

</P>

<A NAME="reloading"></A>
<A NAME="AUTO00039"></A><A NAME="dingp46"></A><P> Similarly, you can adjust
the size of the Navigation Area (including its associated images) by
selecting different icons in the &quot;Nav Size&quot; portion of the
Navigation Area &#151; but don't do it yet!  When you change the size of
the Navigation Area, your browser will reload this file, and you'll find
yourself back at the top of the document instead of here looking at this
paragraph.  This "feature" is built into browsers, and there's no way
around it.  (We tried.  <I>Believe me</I>, we tried.)<SCRIPT>create_link(46);</SCRIPT>

</P>

<A NAME="dingp47"></A>
<P>Now that you know that changing the size of the Navigation Area
will put you back at the top of the current document, go ahead and give the
underlying <nobr><FONT COLOR="#FF0000" SIZE="-2"><B>&deg;</B></FONT><A
HREF="http://www.awl.com/cseng/cgi-bin/cdquery.pl?name=javascript"
ONMOUSEOVER = "self.status = 'What is JavaScript?'; return true" ONMOUSEOUT
= "self.status = self.defaultStatus" TARGET="_top">JavaScript</nobr></A> some
exercise by playing with the size of the Navigation Area.  Later, when I
describe <A HREF="#dingbatSymbol" onMouseOver = "self.status = 'Link to paragraph-specific bookmarking'; return true" onMouseOut = "self.status = self.defaultStatus">paragraph-specific bookmarking</A>,
you'll see how you can mark your place in a document so you can return to
it easily.<SCRIPT>create_link(47);</SCRIPT>

</P>
<A NAME="chunk"></A><A NAME="AUTO00040"></A><A NAME="dingp48"></A><P>
As I noted in my earlier discussion of your <A HREF="#search" onMouseOver = "self.status = 'Link to search options'; return true" onMouseOut = "self.status = self.defaultStatus">search options</A>, there's a trade-off to be made between the size of an HTML File and the effectiveness of your browser's search command.
This put me in a difficult position when designing the CD, because I didn't know what to optimize for. My solution was to kick the problem back to you. There are three copies of each book on this CD, each made up of files of different sizes. You thus have three choices for what I call the books' <I>chunk size</I>.<SCRIPT>create_link(48);</SCRIPT>

</P>
<A NAME="AUTO00042"></A><A NAME="dingp49"></A><P>
<UL><LI>
<A NAME="item"></A><B>Item-length chunking</B> puts each Item in a separate file. The files are small, they load quickly, and they require little memory. Browser-based searches work on only a single Item at a time, however, so you'll probably employ alternative <A HREF="#search" onMouseOver = "self.status = 'Link to search options'; return true" onMouseOut = "self.status = self.defaultStatus">search options</A> much of the time. Item-length chunking is the default.<SCRIPT>create_link(49);</SCRIPT>

</P>

<A NAME="chap"></A><A NAME="AUTO00043"></A><A NAME="dingp50"></A><P>
<LI><B>Chapter-length chunking</B> puts each chapter in a separate file. <A HREF="../EC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>Effective C++</I></A> has seven chapters, plus an additional chunk for each component of the book's "front matter" (dedication, preface, acknowledgments, etc.) and one for the book's Afterword. <A HREF="../MEC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to More Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>More Effective C++</I></A> has six chapters, plus a chunk for each front matter component, a chunk for <SCRIPT>sendmetoo('READ',513,'M');</SCRIPT> onMouseOver = "self.status = 'Link to Recommended Reading'; return true" onMouseOut = "self.status = self.defaultStatus">Recommended Reading</A>, and a chunk for its <SCRIPT>sendmetoo('AUTO','p291','M');</SCRIPT> onMouseOver = "self.status = 'Link to implementation of auto_ptr'; return true" onMouseOut = "self.status = self.defaultStatus"> implementation of <CODE>auto_ptr</CODE></A>. The amount of material in each chunk varies, but most chunks hold enough to fill about 20-40 pages in the printed books.<SCRIPT>create_link(50);</SCRIPT>

</P>

<A NAME="book"></A><A NAME="AUTO00044"></A><A NAME="dingp51"></A><P>
<LI><B>Book-length chunking</B> has a single file for each book. It requires a certain degree of patience and a fair amount of RAM.<SCRIPT>create_link(51);</SCRIPT>

</P>
</UL>

<P><A NAME="dingp52"></A>To select your preferred chunk size, just click on the appropriate icon
in the &quot;Chunks&quot; portion of the <A HREF="#navigation" onMouseOver = "self.status = 'Link to Navigation Area'; return true" onMouseOut = "self.status = self.defaultStatus">Navigation Area</A>. You say it's not obvious which icon is appropriate?  Just move your cursor over each icon and wait a moment. Your browser will then provide you with a short description of the icon's meaning. Depending on your browser, the description will appear either in the browser's status bar or as a pop-up "tool tip"-like window.<SCRIPT>create_link(52);</SCRIPT>

</P>

<P><A NAME="dingp53"></A>
Just as <A HREF="#reloading" onMouseOver = "self.status = 'Link to changing the size of the Navigation Area'; return true" onMouseOut = "self.status = self.defaultStatus">changing the size of the Navigation Area</A>
reloads files and puts you at the top of the current document (see above),
changing your preferred book chunk size has a similar effect. However, if you change your preferred chunk size while inside a book, the page that's reloaded will be the book's <em>table of contents</em>, not the part of the book you're viewing. For example, if you're viewing Item 50 of <em>Effective C++</em> and you change your chunk size setting, you'll find yourself back at the table of contents for <em>Effective C++</em>. In addition, the search applet will reinitialize itself the next time you perform a search. (All this reloading and reinitializing is necessary to make various links work the way they're supposed to, but I'll spare you the details. Suffice it to say we wouldn't inflict this on you if we knew of an easy way to avoid it.)<SCRIPT>create_link(53);</SCRIPT>

</P>

<A NAME="link"></A><P>
<!-- subhead --><FONT ID="iititle"><A NAME="dingp54"></A>Links and Bookmarks</FONT><SCRIPT>create_link(54);</SCRIPT>

</P>

<A NAME="AUTO00045"></A><A NAME="dingp55"></A><P>
There are three kinds of links on this CD: links <I>within</I> a source of information (e.g., a link from one Item in <A HREF="../EC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>Effective C++</I></A> to another Item in that same book), links <I>between</I> sources of information (e.g., from a magazine article to a book Item, from an Item in one book to an Item in the other book, or from a book to a magazine article), and links from the CD to sites on the Internet. Before following a link, it's often useful to know which of these three types you're confronting. This is particularly important when dealing with links to the Internet, as you probably don't want to follow them if you're working off-line.<SCRIPT>create_link(55);</SCRIPT>

</P>

<A NAME="AUTO00046"></A><A NAME="dingp56"></A><P>
There's nothing special about links within a source of information; they look just like normal links in your browser. So if you see a link to Item 14 and you're reading <A HREF="../MEC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to More Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>More Effective C++</I></A>, you can rest assured that that's a link to Item 14 of the same book. Links to a book Item from outside that book prepend "E" or "M" to the Item number, depending on the book the link goes to. Hence, any reference to <SCRIPT>sendmetoo(14,223029,'E');</SCRIPT> onMouseOver = "self.status = 'Link to Item 14 of Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus">Item E14</A> will take you to Item 14 of <A HREF="../EC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>Effective C++</I></A>, while any reference to <SCRIPT>sendmetoo(14,6011,'M');</SCRIPT> onMouseOver = "self.status = 'Link to Item 14 of More Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus">Item M14</A> will take you to Item 14 of <A HREF="../MEC/INDEX.HTM" TARGET="_top" onMouseOver = "self.status = 'Link to More Effective C++'; return true" onMouseOut = "self.status = self.defaultStatus"><I>More Effective C++</I></A>. The encoding doesn't get any more complicated than that, because links to magazine articles or this Introduction to the CD, etc., make their target explicit in the text making up the link.<SCRIPT>create_link(56);</SCRIPT>

</P>

<P>
<A NAME="externalLinkSymbol"></A>
<A NAME="AUTO00047"></A>
<A NAME="dingp57"></A>
Links to Internet sites are preceded by the "<FONT COLOR="#FF0000"
SIZE="-2"><B>&deg;</B></FONT>" symbol. (You probably noticed this symbol
preceding some links earlier in this file.) For example, here's a link to
the web site for the <nobr><FONT COLOR="#FF0000" SIZE="-2"><B>&deg;</B></FONT><A
HREF="http://www.awl.com/cseng/cgi-bin/cdquery.pl?name=wpti" ONMOUSEOVER =
"self.status = 'Wildlife Preservation Trust International Home Page (WPTI)'; return true" ONMOUSEOUT = "self.status = self.defaultStatus"
TARGET="_top">Wildlife</nobr> Preservation Trust International</A>, a conservation
organization whose work I admire and support. However, it doesn't go
directly to that site. Internet addresses change too often for
that. Instead, like all links from this CD to the Internet, it goes to the
Addison-Wesley web site, where it's translated into the correct <nobr><FONT
COLOR="#FF0000" SIZE="-2"><B>&deg;</B></FONT><A
HREF="http://www.awl.com/cseng/cgi-bin/cdquery.pl?name=url" ONMOUSEOVER =
"self.status = 'What is URL?'; return true" ONMOUSEOUT = "self.status =
self.defaultStatus" TARGET="_top">URL</A></nobr> (to the best of AW's knowledge),
and your browser is then automatically forwarded to the correct place in
cyberspace. Going indirect via AW's web site for Internet links imposes a
small performance penalty, but I think it's more than made up for by the
fact that when a URL changes, all AW has to do is update its translation
table, and your CD continues to work.<SCRIPT>create_link(57);</SCRIPT>

</P>