change_stream.hpp

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// Copyright 2009-present 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 <mongocxx/change_stream-fwd.hpp>
#include <mongocxx/client-fwd.hpp>
#include <mongocxx/collection-fwd.hpp>
#include <mongocxx/database-fwd.hpp>
 
#include <bsoncxx/document/view.hpp>
#include <bsoncxx/stdx/optional.hpp>
 
#include <mongocxx/config/prelude.hpp>
 
namespace mongocxx {
namespace v_noabi {
 
class change_stream {
   public:
    class iterator;
 
    MONGOCXX_ABI_EXPORT_CDECL() change_stream(change_stream&& other) noexcept;
 
    MONGOCXX_ABI_EXPORT_CDECL(change_stream&) operator=(change_stream&& other) noexcept;
 
    MONGOCXX_ABI_EXPORT_CDECL() ~change_stream();
 
    MONGOCXX_ABI_EXPORT_CDECL(iterator) begin() const;
 
    MONGOCXX_ABI_EXPORT_CDECL(iterator) end() const;
 
    MONGOCXX_ABI_EXPORT_CDECL(bsoncxx::v_noabi::stdx::optional<bsoncxx::v_noabi::document::view>)
    get_resume_token() const;
 
   private:
    friend ::mongocxx::v_noabi::client;
    friend ::mongocxx::v_noabi::collection;
    friend ::mongocxx::v_noabi::database;
 
    friend ::mongocxx::v_noabi::change_stream::iterator;
 
    change_stream(void* change_stream_ptr);
 
    class impl;
    std::unique_ptr<impl> _impl;
};
 
class change_stream::iterator {
   public:
    // Support input-iterator (caveat of post-increment returning void)
    using difference_type = std::int64_t;
    using value_type = bsoncxx::v_noabi::document::view const;
    using pointer = std::add_pointer<value_type>::type;
    using reference = std::add_lvalue_reference<value_type>::type;
    using iterator_category = std::input_iterator_tag;
 
    MONGOCXX_ABI_EXPORT_CDECL() iterator();
 
    MONGOCXX_ABI_EXPORT_CDECL(bsoncxx::v_noabi::document::view const&) operator*() const;
 
    MONGOCXX_ABI_EXPORT_CDECL(bsoncxx::v_noabi::document::view const*) operator->() const;
 
    MONGOCXX_ABI_EXPORT_CDECL(iterator&) operator++();
 
    MONGOCXX_ABI_EXPORT_CDECL(void) operator++(int);
 
    friend MONGOCXX_ABI_EXPORT_CDECL(bool) operator==(
        change_stream::iterator const&,
        change_stream::iterator const&) noexcept;
 
    friend MONGOCXX_ABI_EXPORT_CDECL(bool) operator!=(
        change_stream::iterator const&,
        change_stream::iterator const&) noexcept;
 
   private:
    friend ::mongocxx::v_noabi::change_stream;
 
    enum class iter_type { k_tracking, k_default_constructed, k_end };
 
    explicit iterator(iter_type type, change_stream const* change_stream);
 
    bool is_exhausted() const;
 
    // iter_type==k_default_constructed is equivalent to _change_stream==nullptr
    iter_type _type;
    change_stream const* _change_stream;
};
 
} // namespace v_noabi
} // namespace mongocxx
 
#include <mongocxx/config/postlude.hpp>