| #ifndef PROTON_NULL_HPP |
| #define PROTON_NULL_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. |
| * |
| */ |
| |
| /// @file |
| /// @copybrief proton::null |
| |
| #include "./internal/config.hpp" |
| #include "./internal/comparable.hpp" |
| #include "./internal/export.hpp" |
| |
| #include <iosfwd> |
| |
| namespace proton { |
| |
| /// The type of the AMQP null value |
| /// |
| /// @see @ref types_page |
| class null : private internal::comparable<null> { |
| public: |
| null() {} |
| #if PN_CPP_HAS_NULLPTR |
| /// Constructed from nullptr literal |
| null(decltype(nullptr)) {} |
| #endif |
| /// null instances are always equal |
| friend bool operator==(const null&, const null&) { return true; } |
| /// null instances are never unequal |
| friend bool operator<(const null&, const null&) { return false; } |
| }; |
| |
| /// Print a null value |
| PN_CPP_EXTERN std::ostream& operator<<(std::ostream&, const null&); |
| |
| } |
| |
| #endif // PROTON_NULL_HPP |