poco/Foundation/include/Poco/Void.h
2012-04-29 18:52:25 +00:00

96 lines
2.6 KiB
C++

//
// Void.h
//
// $Id: //poco/1.4/Foundation/include/Poco/Void.h#1 $
//
// Library: Foundation
// Package: Core
// Module: Void
//
// Definition of the Void class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
#ifndef Foundation_Void_INCLUDED
#define Foundation_Void_INCLUDED
#include "Poco/Foundation.h"
namespace Poco {
class Foundation_API Void
/// A dummy class with value-type semantics,
/// mostly useful as a template argument.
///
/// This class is typically used together with ActiveMethod,
/// if no argument or return value is needed.
{
public:
Void();
/// Creates the Void.
Void(const Void& v);
/// Creates the Void from another Void.
///
/// The philosophical aspects of this operation
/// remain undiscussed for now.
~Void();
/// Destroys the Void.
Void& operator = (const Void& v);
/// Assigns another void.
bool operator ==(const Void& v) const;
/// Will return always true due to Voids having no members.
bool operator !=(const Void& v) const;
/// Will return always false due to Voids having no members.
};
inline bool Void::operator ==(const Void& v) const
{
return true;
}
inline bool Void::operator !=(const Void& v) const
{
return false;
}
} // namespace Poco
#endif // Foundation_Void_INCLUDED