bson_field.h

/*    Copyright 2012 10gen 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 <string>
 
#include "mongo/bson/bsonobj.h"
 
namespace mongo {
 
    template<typename T>
    class BSONFieldValue {
    public:
        BSONFieldValue(const std::string& name, const T& t)
            : _name(name), _t(t) { }
 
        const T& value() const { return _t; }
        const std::string& name() const { return _name; }
 
    private:
        std::string _name;
        T _t;
    };
 
    template<typename T>
    class BSONField {
    public:
        BSONField(const std::string& name)
            : _name(name), _defaultSet(false) {}
 
        BSONField(const std::string& name, const T& defaultVal)
            : _name(name), _default(defaultVal) , _defaultSet(true) {}
 
        BSONFieldValue<T> make(const T& t) const {
            return BSONFieldValue<T>(_name, t);
        }
 
        BSONFieldValue<T> operator()(const T& t) const {
            return BSONFieldValue<T>(_name, t);
        }
 
        const std::string& name() const {
            return _name;
        }
 
        const T& getDefault() const {
            return _default;
        }
 
        bool hasDefault() const {
            return _defaultSet;
        }
 
        std::string operator()() const {
            return _name;
        }
 
        BSONFieldValue<BSONObj> query(const char * q, const T& t) const;
 
        BSONFieldValue<BSONObj> gt(const T& t) const {
            return query("$gt", t);
        }
 
        BSONFieldValue<BSONObj> lt(const T& t) const {
            return query("$lt", t);
        }
 
        BSONFieldValue<BSONObj> ne(const T& t) const {
            return query("$ne", t);
        }
 
    private:
        std::string _name;
        T _default;
        bool _defaultSet;
    };
 
} // namespace mongo