icinga2/base/variant.h

154 lines
3.8 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/) *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License *
* as published by the Free Software Foundation; either version 2 *
* of the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software Foundation *
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#ifndef VARIANT_H
#define VARIANT_H
struct cJSON;
namespace icinga
{
/**
* A type that can hold an arbitrary value.
*
* @ingroup base
*/
class I2_BASE_API Variant
{
public:
inline Variant(void)
: m_Value()
{ }
inline Variant(int value)
: m_Value(static_cast<long>(value))
{ }
inline Variant(long value)
: m_Value(value)
{ }
inline Variant(double value)
: m_Value(value)
{ }
inline Variant(bool value)
: m_Value(static_cast<long>(value))
{ }
inline Variant(const string& value)
: m_Value(value)
{ }
inline Variant(const char *value)
: m_Value(string(value))
{ }
template<typename T>
inline Variant(const shared_ptr<T>& value)
{
Object::Ptr object = dynamic_pointer_cast<Object>(value);
if (!object)
throw_exception(invalid_argument("shared_ptr value type must inherit from Object class."));
m_Value = object;
}
operator long(void) const
{
if (m_Value.type() != typeid(long)) {
if (m_Value.type() == typeid(double)) {
// TODO: log this?
return boost::get<double>(m_Value);
} else {
return boost::lexical_cast<long>(m_Value);
}
} else {
return boost::get<long>(m_Value);
}
}
operator double(void) const
{
if (m_Value.type() != typeid(double)) {
return boost::lexical_cast<double>(m_Value);
} else {
return boost::get<double>(m_Value);
}
}
operator bool(void) const
{
return (static_cast<long>(*this) != 0);
}
operator string(void) const
{
if (m_Value.type() != typeid(string)) {
string result = boost::lexical_cast<string>(m_Value);
m_Value = result;
return result;
} else {
return boost::get<string>(m_Value);
}
}
template<typename T>
operator shared_ptr<T>(void) const
{
if (IsEmpty())
return shared_ptr<T>();
shared_ptr<T> object = dynamic_pointer_cast<T>(boost::get<Object::Ptr>(m_Value));
if (!object)
throw_exception(bad_cast());
return object;
}
bool IsEmpty(void) const;
bool IsScalar(void) const;
bool IsObject(void) const;
template<typename T>
bool IsObjectType(void) const
{
if (!IsObject())
return false;
return (dynamic_pointer_cast<T>(boost::get<Object::Ptr>(m_Value)));
}
static Variant FromJson(cJSON *json);
cJSON *ToJson(void) const;
string Serialize(void) const;
static Variant Deserialize(const string& jsonString);
private:
mutable boost::variant<boost::blank, long, double, string, Object::Ptr> m_Value;
};
}
#endif /* VARIANT_H */