forked from boostorg/smart_ptr
Tidy documentation in smart_ptr
This commit is contained in:
Glen Fernandes committed
1 parent
9f5822f427
commit
540149f019
18 files changed
+2197
-2201
No files matched your search
+86
-86
@@ -1,88 +1,88 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||||
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||||
<html>
|
||||
<head>
|
||||
<title>Smart Pointer Changes</title>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||||
</head>
|
||||
<body bgcolor="#ffffff" text="#000000">
|
||||
<h1><A href="../../index.htm"><img src="../../boost.png" alt="boost.png (6897 bytes)" align="middle" width="277" height="86"
|
||||
border="0"></A>Smart Pointer Changes</h1>
|
||||
<p>The February 2002 change to the Boost smart pointers introduced a number of
|
||||
changes. Since the previous version of the smart pointers was in use for a long
|
||||
time, it's useful to have a detailed list of what changed from a library user's
|
||||
point of view.</p>
|
||||
<p>Note that for compilers that don't support member templates well enough, a
|
||||
separate implementation is used that lacks many of the new features and is more
|
||||
like the old version.</p>
|
||||
<h2>Features Requiring Code Changes to Take Advantage</h2>
|
||||
<ul>
|
||||
<li>
|
||||
The smart pointer class templates now each have their own header file. For
|
||||
compatibility, the <a href="../../boost/smart_ptr.hpp"><boost/smart_ptr.hpp></a>
|
||||
header now includes the headers for the four classic smart pointer class
|
||||
templates.
|
||||
<li>
|
||||
The <b>weak_ptr</b>
|
||||
template was added.
|
||||
<li>
|
||||
The new <b>shared_ptr</b> and <b>shared_array</b> relax the requirement that
|
||||
the pointed-to object's destructor must be visible when instantiating the <b>shared_ptr</b>
|
||||
destructor. This makes it easier to have shared_ptr members in classes without
|
||||
explicit destructors.
|
||||
<li>
|
||||
A custom deallocator can be passed in when creating a <b>shared_ptr</b> or <b>shared_array</b>.
|
||||
<li>
|
||||
<b>shared_static_cast</b> and <b>shared_dynamic_cast</b> function templates are
|
||||
provided which work for <b>shared_ptr</b> and <b>weak_ptr</b> as <b>static_cast</b>
|
||||
and <b>dynamic_cast</b>
|
||||
do for pointers.
|
||||
<li>
|
||||
The self-assignment misfeature has been removed from <b>shared_ptr::reset</b>,
|
||||
although it is still present in <b>scoped_ptr</b>, and in <b>std::auto_ptr</b>.
|
||||
Calling <b>reset</b> with a pointer to the object that's already owned by the <b>shared_ptr</b>
|
||||
results in undefined behavior (an assertion, or eventually a double-delete if
|
||||
assertions are off).
|
||||
<li>
|
||||
The <b>BOOST_SMART_PTR_CONVERSION</b>
|
||||
feature has been removed.
|
||||
<li>
|
||||
<b>shared_ptr<void></b> is now allowed.</li>
|
||||
</ul>
|
||||
<h2>Features That Improve Robustness</h2>
|
||||
<ul>
|
||||
<li>
|
||||
The manipulation of use counts is now <a name="threadsafe">thread safe</a> on
|
||||
Windows, Linux, and platforms that support pthreads. See the <a href="../../boost/detail/atomic_count.hpp">
|
||||
<boost/detail/atomic_count.hpp></a>
|
||||
file for details
|
||||
<li>
|
||||
The new shared_ptr will always delete the object using the pointer it was
|
||||
originally constructed with. This prevents subtle problems that could happen if
|
||||
the last <b>shared_ptr</b> was a pointer to a sub-object of a class that did
|
||||
not have a virtual destructor.</li>
|
||||
</ul>
|
||||
<h2>Implementation Details</h2>
|
||||
<ul>
|
||||
<li>
|
||||
Some bugs in the assignment operator implementations and in <b>reset</b>
|
||||
have been fixed by using the "copy and swap" idiom.
|
||||
<li>
|
||||
Assertions have been added to check preconditions of various functions;
|
||||
however, since these use the new <a href="../../boost/assert.hpp"><boost/assert.hpp></a>
|
||||
header, the assertions are disabled by default.
|
||||
<li>
|
||||
The partial specialization of <b>std::less</b> has been replaced by <b>operator<</b>
|
||||
overloads which accomplish the same thing without relying on undefined
|
||||
behavior.
|
||||
<li>
|
||||
The incorrect overload of <b>std::swap</b> has been replaced by <b>boost::swap</b>,
|
||||
which has many of the same advantages for generic programming but does not
|
||||
violate the C++ standard.</li>
|
||||
</ul>
|
||||
<hr>
|
||||
<p>Revised 1 February 2002</p>
|
||||
<p><small>Copyright 2002 Darin Adler. Distributed under the Boost Software License, Version
|
||||
1.0. See accompanying file <A href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</A> or
|
||||
copy at <A href="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>.</small></p>
|
||||
</body>
|
||||
<head>
|
||||
<title>Smart Pointer Changes</title>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||||
</head>
|
||||
<body text="#000000" bgcolor="#ffffff" link="#0000ff" vlink="#0000ff">
|
||||
<h1><img height="86" alt="boost.png (6897 bytes)" src="../../boost.png"
|
||||
width="277" align="middle" border="0">Smart Pointer Changes</h1>
|
||||
<p>The February 2002 change to the Boost smart pointers introduced a number of
|
||||
changes. Since the previous version of the smart pointers was in use for a long
|
||||
time, it's useful to have a detailed list of what changed from a library user's
|
||||
point of view.</p>
|
||||
<p>Note that for compilers that don't support member templates well enough, a
|
||||
separate implementation is used that lacks many of the new features and is more
|
||||
like the old version.</p>
|
||||
<h2>Features Requiring Code Changes to Take Advantage</h2>
|
||||
<ul>
|
||||
<li>
|
||||
The smart pointer class templates now each have their own header file. For
|
||||
compatibility, the <a href="../../boost/smart_ptr.hpp"><boost/smart_ptr.hpp></a>
|
||||
header now includes the headers for the four classic smart pointer class
|
||||
templates.
|
||||
<li>
|
||||
The <b>weak_ptr</b>
|
||||
template was added.
|
||||
<li>
|
||||
The new <b>shared_ptr</b> and <b>shared_array</b> relax the requirement that
|
||||
the pointed-to object's destructor must be visible when instantiating the <b>shared_ptr</b>
|
||||
destructor. This makes it easier to have shared_ptr members in classes without
|
||||
explicit destructors.
|
||||
<li>
|
||||
A custom deallocator can be passed in when creating a <b>shared_ptr</b> or <b>shared_array</b>.
|
||||
<li>
|
||||
<b>shared_static_cast</b> and <b>shared_dynamic_cast</b> function templates are
|
||||
provided which work for <b>shared_ptr</b> and <b>weak_ptr</b> as <b>static_cast</b>
|
||||
and <b>dynamic_cast</b>
|
||||
do for pointers.
|
||||
<li>
|
||||
The self-assignment misfeature has been removed from <b>shared_ptr::reset</b>,
|
||||
although it is still present in <b>scoped_ptr</b>, and in <b>std::auto_ptr</b>.
|
||||
Calling <b>reset</b> with a pointer to the object that's already owned by the <b>shared_ptr</b>
|
||||
results in undefined behavior (an assertion, or eventually a double-delete if
|
||||
assertions are off).
|
||||
<li>
|
||||
The <b>BOOST_SMART_PTR_CONVERSION</b>
|
||||
feature has been removed.
|
||||
<li>
|
||||
<b>shared_ptr<void></b> is now allowed.</li>
|
||||
</ul>
|
||||
<h2>Features That Improve Robustness</h2>
|
||||
<ul>
|
||||
<li>
|
||||
The manipulation of use counts is now <a name="threadsafe">thread safe</a> on
|
||||
Windows, Linux, and platforms that support pthreads. See the <a href="../../boost/detail/atomic_count.hpp">
|
||||
<boost/detail/atomic_count.hpp></a>
|
||||
file for details
|
||||
<li>
|
||||
The new shared_ptr will always delete the object using the pointer it was
|
||||
originally constructed with. This prevents subtle problems that could happen if
|
||||
the last <b>shared_ptr</b> was a pointer to a sub-object of a class that did
|
||||
not have a virtual destructor.</li>
|
||||
</ul>
|
||||
<h2>Implementation Details</h2>
|
||||
<ul>
|
||||
<li>
|
||||
Some bugs in the assignment operator implementations and in <b>reset</b>
|
||||
have been fixed by using the "copy and swap" idiom.
|
||||
<li>
|
||||
Assertions have been added to check preconditions of various functions;
|
||||
however, since these use the new <a href="../../boost/assert.hpp"><boost/assert.hpp></a>
|
||||
header, the assertions are disabled by default.
|
||||
<li>
|
||||
The partial specialization of <b>std::less</b> has been replaced by <b>operator<</b>
|
||||
overloads which accomplish the same thing without relying on undefined
|
||||
behavior.
|
||||
<li>
|
||||
The incorrect overload of <b>std::swap</b> has been replaced by <b>boost::swap</b>,
|
||||
which has many of the same advantages for generic programming but does not
|
||||
violate the C++ standard.</li>
|
||||
</ul>
|
||||
<hr>
|
||||
<p>$Date$</p>
|
||||
<p><small>Copyright 2002 Darin Adler. Distributed under the Boost Software License, Version
|
||||
1.0. See accompanying file <A href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</A> or
|
||||
copy at <A href="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>.</small></p>
|
||||
</body>
|
||||
</html>
|
||||
Reference in new issue
Block a user