[boost] any_cast improvement

From: Unai Uribarri Rodríguez (unaiur_at_[hidden])
Date: 2003-01-14 16:39:27

I've modified any_cast to work properly with references.

In the boos 1.29 implementation, a code like this:

{
   any x=5;
   ++any_cast<int&>(x);
}

doesn't compile because any_cast tries to instantiate a pointer to int 
&. With the attached patch (which uses ::boost::remove_reference in 
boost/type_traits.hpp to translate int& to int) this code compile and 
works as expected (at least as I expect, setting x to 6).

I believe that it doesn't break the interface for any_cast.

Is there any chance to get the patch accepted?

Good bye!


--- any.hpp.orig	2003-01-14 19:54:44.000000000 +0100
+++ any.hpp	2003-01-14 20:06:02.000000000 +0100
@@ -12,6 +12,7 @@
 #include <typeinfo>
 
 #include "boost/config.hpp"
+#include <boost/type_traits.hpp>
 
 namespace boost
 {
@@ -167,12 +168,22 @@
     template<typename ValueType>
     ValueType any_cast(const any & operand)
     {
-        const ValueType * result = any_cast<ValueType>(&operand);
+        typedef ::boost::remove_reference<ValueType>::type type; 
+        const type * result = any_cast<type>(&operand);
         if(!result)
             throw bad_any_cast();
         return *result;
     }
 
+    template<typename ValueType>
+    ValueType any_cast(any & operand)
+    {
+        typedef ::boost::remove_reference<ValueType>::type type; 
+        type * result = any_cast<type>(&operand);
+        if(!result)
+            throw bad_any_cast();
+        return *result;
+    }
 }
 
 // Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.