Simple inline message construction for exceptions.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@565918 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 58 insertions, 0 deletions

diff --git a/cpp/src/qpid/Msg.h b/cpp/src/qpid/Msg.h
new file mode 100644
index 0000000000..f29235f1ba
--- /dev/null
+++ b/cpp/src/qpid/Msg.h
@@ -0,0 +1,58 @@
+#ifndef QPID_MSG_H
+#define QPID_MSG_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include <sstream>
+#include <iostream>
+
+namespace qpid {
+
+/** A simple wrapper for std::ostringstream that allows
+ * in place construction of a message and automatic conversion
+ * to string.
+ * E.g.
+ *@code
+ * void foo(const std::string&);
+ * foo(Msg() << "hello " << 32);
+ *@endcode
+ * Will construct the string "hello 32" and pass it to foo()
+ */
+struct Msg {
+    std::ostringstream os;
+    Msg() {}
+    Msg(const Msg& m) : os(m.str()) {}
+    std::string str() const { return os.str(); }
+    operator std::string() const { return str(); }
+};
+
+template <class T> const Msg& operator<<(const Msg& m, const T& t) { const_cast<std::ostringstream&>(m.os)<<t; return m; }
+std::ostream& operator<<(std::ostream& o, const Msg& m) { return o<<m.str(); }
+
+/** Construct a message using operator << and append (file:line) */
+#define QPID_MSG(message) Msg() << message << " (" << __FILE__ << ":" << __LINE__ << ")"
+using namespace std;
+
+
+} // namespace qpid
+
+#endif  /*!QPID_MSG_H*/