cursor.hpp

// Copyright 2014 MongoDB Inc.
//
// Licensed 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.
 
#pragma once
 
#include <memory>
 
#include <bsoncxx/document/view.hpp>
#include <bsoncxx/stdx/optional.hpp>
 
#include <mongocxx/config/prelude.hpp>
 
namespace mongocxx {
MONGOCXX_INLINE_NAMESPACE_BEGIN
 
class collection;
 
class MONGOCXX_API cursor {
   public:
    enum class type { k_non_tailable, k_tailable, k_tailable_await };
 
    class MONGOCXX_API iterator;
 
    cursor(cursor&&) noexcept;
 
    cursor& operator=(cursor&&) noexcept;
 
    ~cursor();
 
    iterator begin();
 
    iterator end();
 
   private:
    friend class collection;
    friend class client;
    friend class database;
    friend class index_view;
    friend class cursor::iterator;
 
    MONGOCXX_PRIVATE cursor(void* cursor_ptr,
                            bsoncxx::stdx::optional<type> cursor_type = bsoncxx::stdx::nullopt);
 
    class MONGOCXX_PRIVATE impl;
    std::unique_ptr<impl> _impl;
};
 
class MONGOCXX_API cursor::iterator {
   public:
    using value_type = bsoncxx::document::view;
    using reference = bsoncxx::document::view&;
    using pointer = bsoncxx::document::view*;
    using iterator_category = std::input_iterator_tag;
    using difference_type = std::ptrdiff_t;
 
    const bsoncxx::document::view& operator*() const;
 
    const bsoncxx::document::view* operator->() const;
 
    iterator& operator++();
 
    void operator++(int);
 
   private:
    friend class cursor;
 
    friend MONGOCXX_API bool MONGOCXX_CALL operator==(const iterator&, const iterator&);
    friend MONGOCXX_API bool MONGOCXX_CALL operator!=(const iterator&, const iterator&);
 
    MONGOCXX_PRIVATE bool is_exhausted() const;
 
    MONGOCXX_PRIVATE explicit iterator(cursor* cursor);
 
    // If this pointer is null, the iterator is considered "past-the-end".
    cursor* _cursor;
};
 
MONGOCXX_INLINE_NAMESPACE_END
}  // namespace mongocxx
 
#include <mongocxx/config/postlude.hpp>