#ifndef PROTON_FUNCTION_HPP
#define PROTON_FUNCTION_HPP

/*
 * 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.
 */

namespace proton {

/// A C++03 compatible void no-argument callback function object.
///
/// Used by container::schedule() and event_loop::inject().  In C++11
/// you can use std::bind, std::function or a void-no-argument lambda
/// instead.
///
/// void_function0 is passed by reference, so instances of sub-classes
/// do not have to be heap allocated.  Once passed, the instance must
/// not be deleted until its operator() is called or the container has
/// stopped.
class void_function0 {
  public:
    virtual ~void_function0() {}
    /// Override the call operator with your code.
    virtual void operator()() = 0;
};

}

#endif // PROTON_FUNCTION_HPP
