clean up exception classes

db/repl.h

@@ -107,7 +107,9 @@ namespace mongo {
 #pragma pack()
 
     /* A replication exception */
-    struct SyncException {
+    class SyncException : public DBException {
+    public:
+        virtual const char* what() const throw() { return "sync exception"; }
     };
 
     /* A Source is a source from which we can pull (replicate) data.

stdafx.h

@@ -107,11 +107,16 @@ namespace mongo {
     /* last assert of diff types: regular, wassert, msgassert, uassert: */
     extern Assertion lastAssert[4];
 
-// you can catch these
-    class AssertionException {
+    class DBException : public exception { 
+    public:
+        virtual const char* what() const throw() = 0;
+    };
+
+    class AssertionException : public DBException {
     public:
         string msg;
         AssertionException() { }
+        ~AssertionException() throw() { }
         virtual bool severe() {
             return true;
         }
@@ -121,6 +126,7 @@ namespace mongo {
         virtual string toString() {
             return msg;
         }
+        virtual const char* what() const throw() { return msg.c_str(); }
     };
 
     /* we use the same mechanism for bad things the user does -- which are really just errors */

util/message.h

@@ -177,8 +177,9 @@ namespace mongo {
         bool freeIt;
     };
 
-    class SocketException {
-        
+    class SocketException : public DBException {
+    public:
+        virtual const char* what() const throw() { return "socket exception"; }
     };
 
 } // namespace mongo