SOLVED: Compile issue on Linux x86_64

Attached is the diff, you will need to adjust the file paths.

The problem: It seems that 64bit gcc 4.4.3-4 may be a bit pedantic when it
comes to template expansion.  When presented with the following:

std::pair<void*, int>(0, -1)

It decides that the "0" is an integer which could not possibly under any
circumstances be considered a void * to NULL, or at least not in any sane
world that you and I might inhabit. Therefore the programmer is obviously
attempting to initialize a std::pair<void*, int> with a std:pair<int, int>
and this is just not done in polite circles. Throwing up its hands in
disgust at those silly programmers it spits out a helpful message, exits and
goes for a beer.

Solution: Explain politely to gcc that yes, that really is a void pointer to
null and not the integer 0.

std::pair<void*, int>(static_cast<void *>(0), -1)

I was always under the impression that integer 0 would always be considered
a pointer if used in a context like this.

TomN

--
Thomas Nelson  [email protected]  
--------------------------------------------------------------
Don't anthropomorphize computers, they don't like it.


> -----Original Message-----
> From: Thomas Nelson [mailto:[email protected]]
> Sent: Tuesday, February 16, 2010 9:59 AM
> To: [email protected]
> Subject: [luabind] Compile issue on Linux x86_64
> 
> I just bumped myself up to 0.9 and updated my build scripts.
> 
> Item the first:
> Good job.  I actually get warm fuzzies when a code base gets smaller; it
> means that people are putting thought and effort into keeping it clean and
> clean code is usually good code.  Makes me know that I made the right
> decision when I chose it.
> 
> Item the second:
> I'm getting no problems with the MSVC build (32bit) but on Linux (Fedora12
> x86_64, gcc 4.4.3-4) I'm getting a build error (exact error after note)
> but
> it looks like a conversion between void * and int.
> 
> Anyone else see/solve this yet?  I'm investigating now.
> 
> Error:
> 
> Building CXX object
> external/luabind/CMakeFiles/luabind.dir/src/class.cpp.o
> In file included from
> /usr/lib/gcc/x86_64-redhat-
> linux/4.4.3/../../../../include/c++/4.4.3/utility
> :64,
>                  from /usr/local/include/boost/foreach.hpp:28,
>                  from
> /home/tomn/work/eidolon/external/luabind/src/class.cpp:26:
> /usr/lib/gcc/x86_64-redhat-
> linux/4.4.3/../../../../include/c++/4.4.3/bits/st
> l_pair.h: In constructor 'std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with
> _U1
> = int, _U2 = int, _T1 = void*, _T2 = int]':
> /home/tomn/work/eidolon/external/luabind/./luabind/detail/object_rep.hpp:5
> 8:
> instantiated from here
> /usr/lib/gcc/x86_64-redhat-
> linux/4.4.3/../../../../include/c++/4.4.3/bits/st
> l_pair.h:90: error: invalid conversion from 'int' to 'void*'
> make[2]: *** [external/luabind/CMakeFiles/luabind.dir/src/class.cpp.o]
> Error
> 1
> make[1]: *** [external/luabind/CMakeFiles/luabind.dir/all] Error 2
> make: *** [all] Error 2
> 
> TomN
> 
> --
> Thomas Nelson  [email protected]
> --------------------------------------------------------------
> "If you still have gas, you're not lost".
> - French explorer Pierre Frontage.
> (M.Frontage was so influential in the exploration of North America many
> roads are still named after him.)
> 
> 
> 
> --------------------------------------------------------------------------
> ----
> SOLARIS 10 is the OS for Data Centers - provides features such as DTrace,
> Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW
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> https://lists.sourceforge.net/lists/listinfo/luabind-user

------------------------------------------------------------------------------
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Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW
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Index: E:/development/eidolon/external/luabind/src/class_rep.cpp
===================================================================
--- E:/development/eidolon/external/luabind/src/class_rep.cpp	(revision 448)
+++ E:/development/eidolon/external/luabind/src/class_rep.cpp	(revision 449)
@@ -123,7 +123,7 @@
 {
 	const int size = sizeof(object_rep);
 	char* mem = static_cast<char*>(lua_newuserdata(L, size));
-	return std::pair<void*,void*>(mem, 0);
+	return std::pair<void*,void*>(mem, static_cast<void *>(0));
 }
 
 namespace
Index: E:/development/eidolon/external/luabind/src/inheritance.cpp
===================================================================
--- E:/development/eidolon/external/luabind/src/inheritance.cpp	(revision 448)
+++ E:/development/eidolon/external/luabind/src/inheritance.cpp	(revision 449)
@@ -144,7 +144,7 @@
         return std::make_pair(p, 0);
 
     if (src >= m_vertices.size() || target >= m_vertices.size())
-        return std::pair<void*, int>(0, -1);
+        return std::pair<void*, int>(static_cast<void *>(0), -1);
 
     std::ptrdiff_t const object_offset =
         (char const*)dynamic_ptr - (char const*)p;
@@ -154,7 +154,7 @@
     if (cached.first != cache::unknown)
     {
         if (cached.first == cache::invalid)
-            return std::pair<void*, int>(0, -1);
+            return std::pair<void*, int>(static_cast<void *>(0), -1);
         return std::make_pair((char*)p + cached.first, cached.second);
     }
 
@@ -192,7 +192,7 @@
 
     m_cache.put(src, target, dynamic_id, object_offset, cache::invalid, -1);
 
-    return std::pair<void*, int>(0, -1);
+    return std::pair<void*, int>(static_cast<void *>(0), -1);
 }
 
 void cast_graph::impl::insert(
Index: E:/development/eidolon/external/luabind/luabind/detail/object_rep.hpp
===================================================================
--- E:/development/eidolon/external/luabind/luabind/detail/object_rep.hpp	(revision 448)
+++ E:/development/eidolon/external/luabind/luabind/detail/object_rep.hpp	(revision 449)
@@ -55,7 +55,7 @@
 		std::pair<void*, int> get_instance(class_id target) const
 		{
 			if (m_instance == 0)
-				return std::pair<void*, int>(0, -1);
+				return std::pair<void*, int>(static_cast<void *>(0), -1);
 			return m_instance->get(target);
 		}
 
Index: E:/development/eidolon/external/luabind/luabind/detail/instance_holder.hpp
===================================================================
--- E:/development/eidolon/external/luabind/luabind/detail/instance_holder.hpp	(revision 448)
+++ E:/development/eidolon/external/luabind/luabind/detail/instance_holder.hpp	(revision 449)
@@ -98,7 +98,7 @@
             weak ? weak : get_pointer(p)));
 
         if (!naked_ptr)
-            return std::pair<void*, int>(0, 0);
+            return std::pair<void*, int>(static_cast<void *>(0), 0);
 
         return get_class()->casts().cast(
             naked_ptr