📄 csdn_文档中心_新的c语言：一切都源于fortran.htm
字号:
document.write(year);
document.write(".");
document.write(month);
document.write(".");
document.write(date);
// -->
</SCRIPT>
</B> </TD></TR>
<TR bgColor=#999999>
<TD colSpan=3 height=1></TD></TR></TBODY></TABLE>
<TABLE border=0 width=770>
<TBODY>
<TR>
<TD align=middle bgColor=#fafafa class=td1 vAlign=top width=150><BR>
<SCRIPT src="CSDN_文档中心_新的C语言：一切都源于FORTRAN.files/other.js"></SCRIPT>
</TD>
<TD align=middle width=620>
<TABLE bgColor=#eeeeee border=0 cellPadding=0 cellSpacing=0 width=600>
<TBODY>
<TR bgColor=#ffffff>
<TD align=middle height=10 width=50></TD>
<TD align=right><A href="http://www.csdn.net/">CSDN</A> - <A
href="http://www.csdn.net/develop/">文档中心</A> - <FONT
color=#003399>其他开发语言 </FONT> </TD></TR>
<TR>
<TD align=middle height=5></TD>
<TD align=middle width=500></TD></TR>
<TR>
<TD align=middle bgColor=#003399 height=10><FONT
color=#ffffff>标题</FONT></TD>
<TD><B> 新的C语言：一切都源于FORTRAN</B> MatrixCpp（翻译）
</TD></TR>
<TR>
<TD align=middle height=5></TD>
<TD align=middle width=500></TD></TR>
<TR>
<TD align=middle bgColor=#003399><FONT color=#ffffff>关键字</FONT></TD>
<TD width=500> C，受限指针</TD></TR>
<TR>
<TD align=middle height=5></TD>
<TD align=middle width=500></TD></TR>
<TR>
<TD align=middle bgColor=#003399 height=10><FONT
color=#ffffff>出处</FONT></TD>
<TD height=10> <A
href="http://www.cuj.com%20%20and%20《dr.dobb/" 软件研发》?
s>http://www.cuj.com%20%20and%20《dr.dobb/</A></TD></TR>
<TR>
<TD align=middle height=10></TD>
<TD height=10></TD></TR></TBODY></TABLE><!--文章说明信息结束//-->
<TABLE border=0 width=600>
<TBODY>
<TR>
<TD align=left><BR>
<P class=MsoPlainText style="TEXT-INDENT: 18pt"><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体">此篇文章摘取于即将登载于《</SPAN><SPAN
lang=EN-US style="COLOR: white; FONT-SIZE: 9pt"><A
href="http://www.china-pub.com/computers/common/info.asp?id=13341"><SPAN
style="FONT-SIZE: 10.5pt">Dr.Dobb's 软件研发</SPAN></A></SPAN><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体">》第三期（<SPAN
lang=EN-US>2003年10月）的《The New
C:一切源于FORTRAN》，文章主要是介绍了C99的新特性受限指针，在得到作者Randy
Meyers以及《</SPAN></SPAN><SPAN lang=EN-US
style="COLOR: white; FONT-SIZE: 9pt"><A
href="http://www.china-pub.com/computers/common/info.asp?id=13341"><SPAN
style="FONT-SIZE: 10.5pt">Dr.Dobb's 软件研发</SPAN></A></SPAN><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体">》杂志负责人刘江先生的应允下，把全文的前面的一部分作为文档发表，希望能对大家有所帮助。</SPAN></P>
<P class=MsoPlainText style="TEXT-INDENT: 18pt"><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体"></SPAN> </P>
<P class=MsoPlainText style="TEXT-INDENT: 18pt"><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体"> </P>
<P align=center class=MsoNormal style="TEXT-ALIGN: center"><B><SPAN
style="FONT-FAMILY: 宋体; FONT-SIZE: 14pt; mso-bidi-font-size: 12.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">新的</SPAN></B><B><SPAN
lang=EN-US
style="FONT-SIZE: 14pt; mso-bidi-font-size: 12.0pt">C</SPAN></B><B><SPAN
style="FONT-FAMILY: 宋体; FONT-SIZE: 14pt; mso-bidi-font-size: 12.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">语言：一切都源于</SPAN></B><B><SPAN
lang=EN-US
style="FONT-SIZE: 14pt; mso-bidi-font-size: 12.0pt">FORTRAN</SPAN></B></P>
<P class=MsoPlainText
style="TEXT-INDENT: 18pt; mso-char-indent-count: 2.0; mso-char-indent-size: 9.0pt"><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体">译注：本文是作者<SPAN
lang=EN-US>Randy Meyers在 CUJ杂志开的一个专题系列The New
C的第二篇文章，主要是叙说C99中的新关键字restrict以及</SPAN></SPAN><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt">受限指针（<SPAN
lang=EN-US>restricted
pointers）的历史渊源和使用方式。受限指针作为一种编译器优化代码的方式，是由编译器厂商提供特定的实现，因此这篇文章所谈论的并非在一切实现中都能得到支持，至于如何使用restrict关键字，这篇文章做了很好的说明，</SPAN></SPAN><SPAN
style="FONT-SIZE: 9pt; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 宋体; mso-bidi-font-family: 宋体">期望本文能给关心<SPAN
lang=EN-US>C语言和使用C语言的用户带来帮助。在翻译上，所有译者在翻译过程中有疑惑的术语或者其他一切都以括号形式把原文直接给出，诚心不想给读者半点误导，但是否如愿还需读者的评判，<A
href="mailto:关于本文的一切可以用amstrongest@hotmail.com">关于本文的一切可以用amstrongest@hotmail.com</A>与译者联系和讨论。<?xml:namespace
prefix = o ns = "urn:schemas-microsoft-com:office:office"
/><o:p></o:p></SPAN></SPAN></P>
<P class=MsoNormal><SPAN lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal
style="TEXT-INDENT: 52.5pt; mso-char-indent-count: 5.0; mso-char-indent-size: 10.5pt"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">有时候改进一种语言的最好方式就是让它和三十年前的古老样子更相似</SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">一切都源于</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">（</SPAN><SPAN
lang=EN-US>It all began with FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）。</SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">谈起上面的话，我并不是想说</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">是第一个程序设计语言，但是在上个世纪六十年代（</SPAN><SPAN
lang=EN-US>1960s</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）的一场关于如何在</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中实现参数传递的争论，却意外的使</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">在七十年代（</SPAN><SPAN
lang=EN-US>1970s</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）的超级计算机上面的性能有了巨大的提升，并且导致了九十年代（</SPAN><SPAN
lang=EN-US>1990s</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）一个关于</SPAN><SPAN
lang=EN-US>C</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">语言的新特征被</SPAN><SPAN
lang=EN-US>C99</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">所接受，这就是受限指针（</SPAN><SPAN
lang=EN-US>restricted pointers</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）。而理解受限指针的原始动机的最好方式就是回顾历史，重温发生在</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中的那个由争论所导致的意外。</SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
lang=EN-US> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="TEXT-INDENT: 21pt"><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">和</SPAN><SPAN
lang=EN-US>C</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">不一样的是，在</SPAN><SPAN
lang=EN-US>FORTRAN</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中如果一个函数被分配了一个新值作为参数，传递给函数的实参值将会改变，并且在函数返回时，调用者将会得到新的参数值。考虑下面</SPAN><SPAN
lang=EN-US>Example 1</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">所例举的代码，如果你以</SPAN><SPAN
lang=EN-US>Y</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">作为参数调用</SPAN><SPAN
lang=EN-US>F</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，在</SPAN><SPAN
lang=EN-US>F</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">返回时，</SPAN><SPAN
lang=EN-US>Y</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">值将会是</SPAN><SPAN
lang=EN-US>6</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。</SPAN><SPAN
lang=EN-US>[</SPAN><SPAN
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">译注：下面的程序没有出现变量</SPAN><SPAN
⌨️ 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 + -