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Add FAQ why use_count()?

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[SVN r10604]
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Beman Dawes
2001-07-13 14:07:08 +00:00
parent 65c3f2dc85
commit aea7d0c9c8
1 changed files with 11 additions and 7 deletions
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shared_ptr.htm
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@ -227,24 +227,28 @@ implementation.   The
instantiation of member functions which require a complete type occurs in the <a href="shared_ptr_example2.cpp">shared_ptr_example2.cpp</a>
implementation file.</p>
<h2><a name="FAQ">Frequently Asked Questions</a></h2>
<p><b>Q</b>. Why doesn't <b>shared_ptr</b> have template parameters supplying
<p><b>Q.</b> Why doesn't <b>shared_ptr</b> have template parameters supplying
traits or policies to allow extensive user customization?<br>
<b>A</b>. Parameterization discourages users.&nbsp; <b>Shared_ptr</b> is
<b>A.</b> Parameterization discourages users.&nbsp; <b>Shared_ptr</b> is
carefully crafted to meet common needs without extensive parameterization.
Someday a highly configurable smart pointer may be invented that is also very
easy to use and very hard to misuse.&nbsp; Until then, <b>shared_ptr</b> is the
smart pointer of choice for a wide range of applications.&nbsp; (Those
interested in policy based smart pointers should read <a href="http://cseng.aw.com/book/0,,0201704315,00.html">Modern
C++ Design</a> by Andrei Alexandrescu.)</p>
<p><b>Q</b>. Why doesn't <b>shared_ptr</b> use a linked list implementation?<br>
<b>A</b>. A linked list implementation does not offer enough advantages to
<p><b>Q.</b> Why doesn't <b>shared_ptr</b> use a linked list implementation?<br>
<b>A.</b> A linked list implementation does not offer enough advantages to
offset the added cost of an extra pointer.&nbsp; See <a href="smarttests.htm">timings</a>
page.</p>
<p><b>Q</b>. Why don't <b>shared_ptr</b> (and the other Boost smart pointers)
<p><b>Q.</b> Why don't <b>shared_ptr</b> (and the other Boost smart pointers)
supply an automatic conversion to <b>T*</b>?<br>
<b>A</b>. Automatic conversion is believed to be too error prone.</p>
<b>A.</b> Automatic conversion is believed to be too error prone.</p>
<p><b>Q.</b> Why does <b>shared_ptr</b> supply use_count()?<br>
<b>A.</b> As an aid to writing test cases and debugging displays. One of the
progenitors had use_count(), and it was useful in tracking down bugs in a
complex project that turned out to have cyclic-dependencies.</p>
<hr>
<p>Revised <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->12 July, 2001<!--webbot bot="Timestamp" endspan i-checksum="21065" -->
<p>Revised <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->13 July, 2001<!--webbot bot="Timestamp" endspan i-checksum="21067" -->
</p>
<p><EFBFBD> Copyright Greg Colvin and Beman Dawes 1999. Permission to copy, use,
modify, sell and distribute this document is granted provided this copyright