From 6b0bfad6bfffd40f0744071c53ab69bb6a0f0d19 Mon Sep 17 00:00:00 2001
From: Emil Dotchevski <emil@revergestudios.com>
Date: Mon, 17 Jan 2011 07:01:35 +0000
Subject: [PATCH] Converted exception_ptr from a shared_ptr typedef to a
 stand-alone class to allow simpler declaration of namespace boost { class
 exception_ptr; }

[SVN r68202]
---
 .../boost/exception/detail/exception_ptr.hpp  | 44 ++++++++++++++++---
 .../exception/errinfo_nested_exception.hpp    |  2 +-
 2 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/include/boost/exception/detail/exception_ptr.hpp b/include/boost/exception/detail/exception_ptr.hpp
index 74f451c..af8f6f8 100644
--- a/include/boost/exception/detail/exception_ptr.hpp
+++ b/include/boost/exception/detail/exception_ptr.hpp
@@ -29,10 +29,42 @@
 namespace
 boost
     {
-    typedef shared_ptr<exception_detail::clone_base const> exception_ptr;
-
+    class exception_ptr;
+    void rethrow_exception( exception_ptr const & );
     exception_ptr current_exception();
 
+    class
+    exception_ptr
+        {
+        typedef boost::shared_ptr<exception_detail::clone_base const> impl;
+        impl ptr_;
+        friend void rethrow_exception( exception_ptr const & );
+        typedef exception_detail::clone_base const * (impl::*unspecified_bool_type)() const;
+        public:
+        exception_ptr()
+            {
+            }
+        explicit
+        exception_ptr( impl const & ptr ):
+            ptr_(ptr)
+            {
+            }
+        bool
+        operator==( exception_ptr const & other ) const
+            {
+            return ptr_==other.ptr_;
+            }
+        bool
+        operator!=( exception_ptr const & other ) const
+            {
+            return ptr_!=other.ptr_;
+            }
+        operator unspecified_bool_type() const
+            {
+            return ptr_?&impl::get:0;
+            }
+        };
+
     template <class T>
     inline
     exception_ptr
@@ -89,7 +121,7 @@ boost
                 throw_function(BOOST_CURRENT_FUNCTION) <<
                 throw_file(__FILE__) <<
                 throw_line(__LINE__);
-            static exception_ptr ep(new exception_detail::clone_impl<Exception>(c));
+            static exception_ptr ep(shared_ptr<exception_detail::clone_base const>(new exception_detail::clone_impl<Exception>(c)));
             return ep;
             }
 
@@ -272,7 +304,7 @@ boost
                 success:
                     {
                     BOOST_ASSERT(e!=0);
-                    return exception_ptr(e);
+                    return exception_ptr(shared_ptr<exception_detail::clone_base const>(e));
                     }
                 case exception_detail::clone_current_exception_result::
                 bad_alloc:
@@ -299,7 +331,7 @@ boost
                     catch(
                     exception_detail::clone_base & e )
                         {
-                        return exception_ptr(e.clone());
+                        return exception_ptr(shared_ptr<exception_detail::clone_base const>(e.clone()));
                         }
                     catch(
                     std::domain_error & e )
@@ -421,7 +453,7 @@ boost
     rethrow_exception( exception_ptr const & p )
         {
         BOOST_ASSERT(p);
-        p->rethrow();
+        p.ptr_->rethrow();
         }
 
     inline
diff --git a/include/boost/exception/errinfo_nested_exception.hpp b/include/boost/exception/errinfo_nested_exception.hpp
index e4e75d9..29c6f4a 100644
--- a/include/boost/exception/errinfo_nested_exception.hpp
+++ b/include/boost/exception/errinfo_nested_exception.hpp
@@ -12,7 +12,7 @@ boost
     namespace exception_detail { class clone_base; };
     template <class Tag,class T> class error_info;
     template <class T> class shared_ptr;
-    typedef shared_ptr<exception_detail::clone_base const> exception_ptr;
+    class exception_ptr;
     typedef error_info<struct errinfo_nested_exception_,exception_ptr> errinfo_nested_exception;
     }