[Boost-commit] svn:boost r4498

From: fmhess_at_[hidden]
Date: 2007-06-08 13:31:58

Author: fmhess
Date: 2007-06-08 13:31:57 EDT (Fri, 08 Jun 2007)
New Revision: 4498
URL: http://svn.boost.org/trac/boost/changeset/4498

Log:
Updated thread_safe_signals FAQ wrt using with Qt.

Text files modified: 
   sandbox/libs/thread_safe_signals/doc/faq.xml |    60 ++++++++------------------------------- 
   1 files changed, 13 insertions(+), 47 deletions(-)

Modified: sandbox/libs/thread_safe_signals/doc/faq.xml
==============================================================================
--- sandbox/libs/thread_safe_signals/doc/faq.xml	(original)
+++ sandbox/libs/thread_safe_signals/doc/faq.xml	2007-06-08 13:31:57 EDT (Fri, 08 Jun 2007)
@@ -24,8 +24,10 @@
       </question>
       <answer>
         <para>Yes, if the ThreadingModel template parameter of the signal is set to
-        boost::signals::multi_threaded.  If you use thread-safe signals
-        in your code, you will also have to link to libboost_thread.</para>
+        <code>boost::signals::multi_threaded</code>, or if it is set to
+        <code>boost::signals::auto_threaded</code> and boost has detected thread support
+        in the compiler's current translation mode.  If you use <code>boost::signals::multi_threaded</code>,
+        you will also have to link to libboost_thread.</para>
       </answer>
     </qandaentry>
     <qandaentry>
@@ -35,10 +37,16 @@
       <answer>
         <para>When building with Qt, the Moc keywords
         <code>signals</code> and <code>slots</code> are defined using
-        preprocessor macros, causing programs using Boost.Signals and
-        Qt together to fail to compile.</para>
+        preprocessor macros, causing a conflict with the <code>boost::signals</code>
+        namespace.  For thread_safe_signals, <code>boost::signals</code> is actually
+        just an alias to <code>boost::signalslib</code>.  So by always using the
+        namespace <code>boost::signalslib</code> instead of
+        <code>boost::signals</code> in your
+        code, you can avoid any conflict with the Qt <code>signals</code> macro.
+        </para>
 
-        <para><emphasis>For Qt 4.1 and later</emphasis>, This behavior
+        <para>Alternatively, for <emphasis>Qt 4.1 and later</emphasis>
+        the <code>signals</code> and <code>slots</code> macros
         can be turned off in Qt on a per-project or per-file basis
         with the <code>no_keywords</code> option.  This works with
         out-of-the-box builds of Boost and Qt. You do not need to
@@ -62,48 +70,6 @@
         complete examples and a survey of the strengths of the two
         systems.</para>
 
-        <para><emphasis>Older versions of Qt</emphasis> did not
-        provide a reliable mechanism for avoiding these unfriendly,
-        all lower-case `keyword'-like macros.  Although this is a
-        problem with Qt and not Boost.Signals, a user can use the two
-        systems together with a little extra effort. There are two
-        ways to do this:</para>
-
-        <para>The first way involves defining
-        the <code>BOOST_SIGNALS_NAMESPACE</code>
-        macro to some other identifier (e.g., <code>signalslib</code>)
-        when building and using the Boost.Signals library. Then the
-        namespace of the Boost.Signals library will be
-        <code>boost::BOOST_SIGNALS_NAMESPACE</code> instead of
-        <code>boost::signals</code>. To retain the original namespace
-        name in translation units that do not interact with Qt, you
-        can use a namespace alias:</para>
-
-        <programlisting>
-  namespace boost {
-    namespace signals = BOOST_SIGNALS_NAMESPACE;
-  }
-</programlisting>
-
-        <para>The second way, provided by Frank Hess, involves
-        creating a header <code>signalslib.hpp</code> that contains
-          the following code:</para>
-
-        <programlisting>#ifdef signals
-#error "signalslib.hpp must be included before any qt header"
-#endif
-
-#include &lt;boost/signal.hpp&gt;
-namespace boost
-{
-  namespace signalslib = signals;
-}</programlisting>
-
-        <para>This header must be included before any Qt headers. Once
-        it has been included, you can refer to the Signals library via
-        the namespace <code>boost::signalslib</code>. This option is
-        preferable to the first option because it can be used without
-        recompiling the Signals library binary. </para>
       </answer>
     </qandaentry>
   </qandaset>