[Boost-commit] svn:boost r72188 - in trunk/boost/spirit/home/support/utree: . detail

Subject: [Boost-commit] svn:boost r72188 - in trunk/boost/spirit/home/support/utree: . detail
From: blelbach_at_[hidden]
Date: 2011-05-26 14:16:38

Author: wash
Date: 2011-05-26 14:16:38 EDT (Thu, 26 May 2011)
New Revision: 72188
URL: http://svn.boost.org/trac/boost/changeset/72188

Log:
Emit more accurate exceptions when back() or front() is called on an empty utree
list.

Text files modified: 
   trunk/boost/spirit/home/support/utree/detail/utree_detail2.hpp |    48 ++++++++++++++++++++++++++------------- 
   trunk/boost/spirit/home/support/utree/utree.hpp                |    19 +++++++++++++++                         
   2 files changed, 50 insertions(+), 17 deletions(-)

Modified: trunk/boost/spirit/home/support/utree/detail/utree_detail2.hpp
==============================================================================
--- trunk/boost/spirit/home/support/utree/detail/utree_detail2.hpp	(original)
+++ trunk/boost/spirit/home/support/utree/detail/utree_detail2.hpp	2011-05-26 14:16:38 EDT (Thu, 26 May 2011)
@@ -1302,16 +1302,20 @@
             return p->front();
         if (get_type() == type::range_type)
         {
-            BOOST_ASSERT(r.first != 0);
+            if (!r.first)
+                BOOST_THROW_EXCEPTION(
+                    empty_exception("front() called on empty utree range"));
             return r.first->val;
         }
 
         // otherwise...
-        if (get_type() != type::list_type || l.first == 0)
+        if (get_type() != type::list_type)
             BOOST_THROW_EXCEPTION(
                 bad_type_exception
-                    ("front() called on non-list utree type",
-                     get_type()));
+                    ("front() called on non-list utree type", get_type()));
+        else if (!l.first)
+            BOOST_THROW_EXCEPTION(
+                empty_exception("front() called on empty utree list"));
 
         return l.first->val;
     }
@@ -1322,16 +1326,20 @@
             return p->back();
         if (get_type() == type::range_type)
         {
-            BOOST_ASSERT(r.last != 0);
+            if (!r.last)
+                BOOST_THROW_EXCEPTION(
+                    empty_exception("back() called on empty utree range"));
             return r.last->val;
         }
 
         // otherwise...
-        if (get_type() != type::list_type || l.last == 0)
+        if (get_type() != type::list_type) 
             BOOST_THROW_EXCEPTION(
                 bad_type_exception
-                    ("back() called on non-list utree type",
-                     get_type()));
+                    ("back() called on non-list utree type", get_type()));
+        else if (!l.last)
+            BOOST_THROW_EXCEPTION(
+                empty_exception("back() called on empty utree list"));
 
         return l.last->val;
     }
@@ -1342,16 +1350,20 @@
             return ((utree const*)p)->front();
         if (get_type() == type::range_type)
         {
-            BOOST_ASSERT(r.first != 0);
+            if (!r.first)
+                BOOST_THROW_EXCEPTION(
+                    empty_exception("front() called on empty utree range"));
             return r.first->val;
         }
 
         // otherwise...
-        if (get_type() != type::list_type || l.first == 0)
+        if (get_type() != type::list_type)
             BOOST_THROW_EXCEPTION(
                 bad_type_exception
-                    ("front() called on non-list utree type",
-                     get_type()));
+                    ("front() called on non-list utree type", get_type()));
+        else if (!l.first)
+            BOOST_THROW_EXCEPTION(
+                empty_exception("front() called on empty utree list"));
 
         return l.first->val;
     }
@@ -1362,16 +1374,20 @@
             return ((utree const*)p)->back();
         if (get_type() == type::range_type)
         {
-            BOOST_ASSERT(r.last != 0);
+            if (!r.last)
+                BOOST_THROW_EXCEPTION(
+                    empty_exception("back() called on empty utree range"));
             return r.last->val;
         }
 
         // otherwise...
-        if (get_type() != type::list_type || l.last == 0)
+        if (get_type() != type::list_type) 
             BOOST_THROW_EXCEPTION(
                 bad_type_exception
-                    ("back() called on non-list utree type",
-                     get_type()));
+                    ("back() called on non-list utree type", get_type()));
+        else if (!l.last)
+            BOOST_THROW_EXCEPTION(
+                empty_exception("back() called on empty utree list"));
 
         return l.last->val;
     }

Modified: trunk/boost/spirit/home/support/utree/utree.hpp
==============================================================================
--- trunk/boost/spirit/home/support/utree/utree.hpp	(original)
+++ trunk/boost/spirit/home/support/utree/utree.hpp	2011-05-26 14:16:38 EDT (Thu, 26 May 2011)
@@ -48,6 +48,11 @@
        precondition is violated as the `utree` instance holds some other type.
     */
     struct bad_type_exception /*: utree_exception*/;
+
+    /*`The `empty_exception` is thrown whenever a precondition of a list
+       or range utree method is violated due to the list or range being empty. 
+    */
+    struct empty_exception /*: utree_exception*/;
     //]
 
     //[utree_types
@@ -137,9 +142,21 @@
 
         virtual ~bad_type_exception() throw() {}
 
-        virtual const char* what() const throw()
+        virtual char const* what() const throw()
         { return msg.c_str(); }
     };
+    
+    struct empty_exception : utree_exception
+    {
+        char const* msg;
+
+        empty_exception(char const* error) : msg(error) {}
+        
+        virtual ~empty_exception() throw() {}
+
+        virtual char const* what() const throw()
+        { return msg; }
+    };
 
     ///////////////////////////////////////////////////////////////////////////
     // A typed string with parametric Base storage. The storage can be any