Exheredludis/paludis/util/singleton.hh
Saleem Abdulrasool 294dc29f7f util: avoid GNU extension usage
Redeclaration of forward declares is a GNU extension.  This is unnecessary as it
has been already forward declarated at the appropriate point.  This helps
compatibility with clang.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
2013-11-02 14:19:50 -07:00

83 lines
2.1 KiB
C++

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2005, 2006, 2007, 2010 Ciaran McCreesh
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis 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., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef PALUDIS_GUARD_PALUDIS_SINGLETON_HH
#define PALUDIS_GUARD_PALUDIS_SINGLETON_HH 1
#include <paludis/util/attributes.hh>
/** \file
* Singleton pattern.
*
* \ingroup g_oo
*
* \section Examples
*
* - None at this time.
*/
namespace paludis
{
/**
* Singletons have a single instance and are created when first used.
*
* \ingroup g_oo
* \nosubgrouping
*/
template <typename OurType_>
class PALUDIS_VISIBLE Singleton
{
private:
static OurType_ * * _get_instance_ptr();
class DeleteOnDestruction;
friend class DeleteOnDestruction;
static void _delete(OurType_ * const p);
public:
///\name Basic operations
///\{
Singleton() = default;
Singleton(const Singleton &) = delete;
const Singleton & operator= (const Singleton &) = delete;
///\}
///\name Singleton operations
///\{
/**
* Fetch our instance.
*/
static OurType_ * get_instance()
PALUDIS_ATTRIBUTE((warn_unused_result));
/**
* Destroy our instance.
*/
static void destroy_instance();
///\}
};
}
#endif