cpp/include/proton/annotation_key.hpp

#ifndef PROTON_ANNOTATION_KEY_HPP
#define PROTON_ANNOTATION_KEY_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.
 *
 */

#include "./scalar_base.hpp"
#include "./symbol.hpp"

#include <proton/type_compat.h>

/// @file
/// @copybrief proton::annotation_key

namespace proton {

/// A key for use with AMQP annotation maps.
///
/// An annotation_key can contain either a uint64_t or a proton::symbol.
class annotation_key : public scalar_base {
  public:
    /// An empty annotation key.
    annotation_key() {}

    /// Construct from any type that can be assigned.
    template <class T> annotation_key(const T& x) { *this = x; }

    /// @name Assign from a uint64_t or symbol.
    /// @{
    annotation_key& operator=(uint64_t x) { put_(x); return *this; }
    annotation_key& operator=(const symbol& x) { put_(x); return *this; }
    /// @}

    /// @name Extra conversions for strings, treated as codec::SYMBOL.
    /// @{
    annotation_key& operator=(const std::string& x) { put_(symbol(x)); return *this; }
    annotation_key& operator=(const char *x) { put_(symbol(x)); return *this; }
    /// @}

    /// @cond INTERNAL
  friend class message;
  friend class codec::decoder;
    /// @endcond
};

/// @cond INTERNAL
/// Primary template for get<T>(message_id), specialized for legal types.
template <class T> T get(const annotation_key& x);
/// @endcond

/// Get the uint64_t value or throw conversion_error.
///
/// @relatedalso annotation_key
template<> inline uint64_t get<uint64_t>(const annotation_key& x) { return internal::get<uint64_t>(x); }

/// Get the @ref symbol value or throw conversion_error.
///
/// @relatedalso annotation_key
template<> inline symbol get<symbol>(const annotation_key& x) { return internal::get<symbol>(x); }

/// Get the @ref binary value or throw conversion_error.
///
/// @copydoc scalar::coerce
/// @relatedalso annotation_key
template<class T> T coerce(const annotation_key& x) { return internal::coerce<T>(x); }

} // proton

#endif // PROTON_ANNOTATION_KEY_HPP