<TD align=middle width=500></TD></TR>
        <TR>
          <TD align=middle bgColor=#003399 height=10><FONT 
            color=#ffffff>標題</FONT></TD>
          <TD><B>&nbsp;&nbsp;&nbsp;&nbsp;介紹一個很好用的overwrite 
            迭代器</B>&nbsp;&nbsp;&nbsp;&nbsp;easyjoy（翻譯） </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>關鍵字</FONT></TD>
          <TD width=500>&nbsp;&nbsp;&nbsp;&nbsp;迭代器 容器 拷貝</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>出處</FONT></TD>
          <TD height=10>&nbsp;&nbsp;&nbsp;&nbsp;<A 
            href="http://cuj/">http://cuj/</A></TD></TR>
        <TR>
          <TD align=middle height=10></TD>
          <TD height=10></TD></TR></TBODY></TABLE><!--文章說明信息結束//-->
      <TABLE border=0 width=600>
        <TBODY>
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          <TD align=left><BR>
            <P align=center class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center"><B><SPAN 
            style="COLOR: blue; FONT-FAMILY: 宋體; FONT-SIZE: 16pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">介紹一個很好用的</SPAN></B><B><SPAN 
            lang=EN-US 
            style="COLOR: blue; FONT-SIZE: 16pt; mso-bidi-font-size: 12.0pt">overwrite 
            </SPAN></B><B><SPAN 
            style="COLOR: blue; FONT-FAMILY: 宋體; FONT-SIZE: 16pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">迭代器</SPAN></B><B><SPAN 
            lang=EN-US 
            style="COLOR: blue; FONT-SIZE: 16pt; mso-bidi-font-size: 12.0pt"><?xml:namespace 
            prefix = o ns = "urn:schemas-microsoft-com:office:office" 
            /><o:p></o:p></SPAN></B></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【原標題】</SPAN><SPAN 
            lang=EN-US>C++ Tip</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＃</SPAN><SPAN 
            lang=EN-US>11 Overwrite Iterator</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【出處】</SPAN><SPAN 
            lang=EN-US>C++ User Journal December 2002 Volume 20 Number 
            12</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【作者】</SPAN><SPAN 
            lang=EN-US>Ray Virzi</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【譯者】</SPAN><SPAN 
            lang=EN-US>easyjoy</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【關鍵字】迭代器</SPAN> 
            <SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">容器</SPAN> 
            <SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">拷貝</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【摘要】本文介紹了一個新迭代器（</SPAN><SPAN 
            lang=EN-US>overwrite_iterator</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">），可以在不清除容器原有元素的情況下，很方便的直接覆蓋拷貝來自某個序列的新元素；并根據需要自動增長容器的大小。</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">【正文】</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0; mso-char-indent-size: 10.5pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">如果你要把一個序列（</SPAN><SPAN 
            lang=EN-US>sequence</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）拷貝到一個容器（</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）中去，通常你用</SPAN><SPAN 
            lang=EN-US>std::copy</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">算法，代碼如下：</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><SPAN lang=EN-US 
            style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto">std::copy(start, 
            end, std::back_inserter(container));<o:p></o:p></SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0; mso-char-indent-size: 10.5pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">這里，</SPAN><SPAN 
            lang=EN-US>start</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">和</SPAN><SPAN 
            lang=EN-US>end</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">是輸入序列（假設有</SPAN><SPAN 
            lang=EN-US>N</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">各元素）的迭代器（</SPAN><SPAN 
            lang=EN-US>iterator</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">），</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">是一個容器，該容器的接口包含函數</SPAN><SPAN 
            lang=EN-US>push_back</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">。假設</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">開始是空的，那么</SPAN><SPAN 
            lang=EN-US>copy</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">完畢后它就包含</SPAN><SPAN 
            lang=EN-US>N</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">個元素，并且順序與原來隊列中的元素順序一樣。標準庫提供的</SPAN><SPAN 
            lang=EN-US>back_inserter</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">模板函數很方便，因為它為</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回一個</SPAN><SPAN 
            lang=EN-US>back_insert_iterator</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">迭代器，這樣，復制的元素都被追加到</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的末尾了。</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0; mso-char-indent-size: 10.5pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">現在假設</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">開始非空（例如：</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">必須在循環中反復被使用好幾次）。那么，要達到原來的目標，必須先調用</SPAN><SPAN 
            lang=EN-US>clear</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">函數然后才能插入新序列。這會導致舊的元素對象被析構，新添加進來的被構造。不僅如此，</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">自身使用的動態內存也會被釋放然后又創建，就像</SPAN><SPAN 
            lang=EN-US>list</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，</SPAN><SPAN 
            lang=EN-US>map</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，</SPAN><SPAN 
            lang=EN-US>set</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的節點。某些</SPAN><SPAN 
            lang=EN-US>vector</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的實現在調用</SPAN><SPAN 
            lang=EN-US>clear</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的時候甚至會釋放所有內存。通常，考慮到在一個已有的元素上直接</SPAN><SPAN 
            lang=EN-US>copy</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">覆蓋更高效。也許你會這樣做：</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><SPAN lang=EN-US 
            style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto">std::copy(start, 
            end, container.begin());<o:p></o:p></SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0; mso-char-indent-size: 10.5pt"><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">在這里你在</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的頭部執行了</SPAN><SPAN 
            lang=EN-US>copy</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US>over</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（覆蓋賦值）操作，但是，如果</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的大小小于輸入序列的長度</SPAN><SPAN 
            lang=EN-US>N</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的話，這段代碼會導致崩潰（</SPAN><SPAN 
            lang=EN-US>crash</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）?，F在需要一個新迭代器，這個新迭代器在到達</SPAN><SPAN 
            lang=EN-US>container</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的末尾之前執行</SPAN><SPAN 
            lang=EN-US>copy</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US>over</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">操作，之后執行</SPAN><SPAN 
            lang=EN-US>append</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">操作。我給這個迭代器命名為</SPAN><SPAN 
            lang=EN-US>overwrite iterator</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，其定義見代碼清單</SPAN><SPAN 
            lang=EN-US>1</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">；并遵循標準庫的慣例，提供兩個輔助模板函數（</SPAN><SPAN 
            lang=EN-US>helper template function</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">），來從指定容器構造</SPAN><SPAN 
            lang=EN-US>overwrite iterator</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，見代碼清單</SPAN><SPAN 
            lang=EN-US>2</SPAN><SPAN 
            style="FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">。</SPAN></P>
            <P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN 
            lang=EN-US>&nbsp;<o:p></o:p></SPAN></P>
            <P class=MsoNormal