Added walkExceptionCause helper function.

source/mijin/util/exception.hpp

@@ -48,5 +48,30 @@ inline decltype(auto) ensure(TCondition&& condition, TExceptionArgs&&... args)
     }
     return std::forward<TCondition>(condition);
 }
+
+template<typename TFunc>
+void walkExceptionCause(const std::exception_ptr& cause, TFunc func)
+{
+    if (cause)
+    {
+        try
+        {
+            std::rethrow_exception(cause);
+        }
+        catch(Exception& exc)
+        {
+            func(exc);
+            walkExceptionCause(exc.getCause(), std::move(func));
+        }
+        catch(std::exception& exc)
+        {
+            func(exc);
+        }
+        catch(...)
+        {
+            func(nullptr);
+        }
+    }
+}
 } // namespace mijin
 #endif // MIJIN_UTIL_EXCEPTION_HPP_INCLUDED