[Boost-commit] svn:boost r71686 - sandbox/block_ptr/libs/smart_ptr/doc

Subject: [Boost-commit] svn:boost r71686 - sandbox/block_ptr/libs/smart_ptr/doc
From: phil_at_[hidden]
Date: 2011-05-02 21:30:09

Author: pbouchard
Date: 2011-05-02 21:30:08 EDT (Mon, 02 May 2011)
New Revision: 71686
URL: http://svn.boost.org/trac/boost/changeset/71686

Log:
* Added documentation on explicit cyclic() function
Text files modified: 
   sandbox/block_ptr/libs/smart_ptr/doc/tutorial.html |    24 +++++++++++++++++++++++-                
   1 files changed, 23 insertions(+), 1 deletions(-)

Modified: sandbox/block_ptr/libs/smart_ptr/doc/tutorial.html
==============================================================================
--- sandbox/block_ptr/libs/smart_ptr/doc/tutorial.html	(original)
+++ sandbox/block_ptr/libs/smart_ptr/doc/tutorial.html	2011-05-02 21:30:08 EDT (Mon, 02 May 2011)
@@ -88,7 +88,7 @@
   
   <h2><a name="advanced" id="advanced"></a>Advanced</h2>
 
-  <p>When STL containers are made out of objects having members of type <i>block_ptr&#60;T&#62;</i> then it will be desirable to have all of the allocated nodes 
+  <p>Firstly when STL containers are made out of objects having members of type <i>block_ptr&#60;T&#62;</i> then it will be desirable to have all of the allocated nodes 
   and its members part of the same <i>set</i>.  This way all of the newly allocated <i>block_ptr&#60;T&#62;</i> will be referring to the same <i>set</i> header.
   In order to do so, we must tell the container in question a new allocator that will be used to instantiate the nodes.  This allocator is called: 
   <i>block_allocator&#60;T&#62;</i>.  For example:</p>
@@ -98,6 +98,28 @@
   c.push_back(make_block&#60;int&#62;(11));
   </pre>
 
+  <p>Secondly in the case where a cyclic set is being destroyed, in order to prevent <i>block_ptr</i>s member pointers from accessing an object that is already being 
+  destroyed a function is provided to explicitly prevent such a scenario:</p>
+
+  <pre>  
+  struct A
+  {
+      block_ptr&#60;A&#62; p;
+  
+      void foo() {}
+      
+      ~A()
+      {
+          if (! p.cyclic())
+              p->foo();
+      }
+  };
+  
+  block_ptr&#60;A&#62; p;
+  p = make_block&#60;A&#62;();
+  p-&#62;p = p;
+  </pre>
+
   <h2><a name="caveat" id="caveat"></a>Caveat</h2>
   
   <p>Hierarchies with multiple inheritance without virtual tables will cause undefined behavior if a pointer to a derived class is assigned to a pointer of one