1 files changed, 18 insertions, 1 deletions
diff --git a/cpp/src/IceUtil/Exception.cpp b/cpp/src/IceUtil/Exception.cpp
index adcced92d33..5208bfe0a2d 100644
--- a/cpp/src/IceUtil/Exception.cpp
+++ b/cpp/src/IceUtil/Exception.cpp
@@ -8,6 +8,8 @@
 // **********************************************************************
 
 #include <IceUtil/Exception.h>
+#include <IceUtil/StaticMutex.h>
+#include <ostream>
 
 using namespace std;
 
@@ -52,6 +54,21 @@ IceUtil::Exception::ice_print(ostream& out) const
     out << ice_name();
 }
 
+const char*
+IceUtil::Exception::what() const throw()
+{
+    StaticMutex::Lock lock(globalMutex);
+    {
+        if(_str.empty())
+        {
+            stringstream s;
+            ice_print(s);
+            _str = s.str(); // Lazy initialization.
+        }
+    }
+    return _str.c_str();
+}
+
 IceUtil::Exception*
 IceUtil::Exception::ice_clone() const
 {
@@ -154,7 +171,7 @@ IceUtil::IllegalArgumentException::ice_throw() const
 ostream&
 IceUtil::operator<<(ostream& out, const IceUtil::IllegalArgumentException& ex)
 {
-    ex.ice_print(out);
+    ex.ice_print(out);
     out << ": " << ex.reason;
     return out;
 }