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// -*- mode: c++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; coding: utf-8-unix -*-
// ***** BEGIN LICENSE BLOCK *****
//////////////////////////////////////////////////////////////////////////
// Copyright (c) 2011-2014 RALOVICH, Kristóf //
// //
// 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 3 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. //
// //
//////////////////////////////////////////////////////////////////////////
// ***** END LICENSE BLOCK *****
#pragma once
#include <memory>
//#define PSO_LAZYSINGLETON_DEBUG 1
#ifdef PSO_LAZYSINGLETON_DEBUG
# include <cstdio>
# define lazySingletonTrace() \
do \
{ \
::fprintf(stdout, "%s: %s:%d\n", __PRETTY_FUNCTION__, __FILE__, __LINE__); \
::fflush(stdout); \
} while(false)
#else // !PSO_LAZYSINGLETON_DEBUG
# define lazySingletonTrace() do { } while(false)
#endif // !PSO_LAZYSINGLETON_DEBUG
namespace antpm
{
template <class T>
class ClassInstantiator
{
public:
virtual ~ClassInstantiator() {}
protected:
static /*inline*/ T* instantiate();
// template < class P1 >
// static inline T* instantiate(P1 p1);
template <class T1, class I1> friend class LazySingleton;
};
template <class T, class I = ClassInstantiator<T> >
class LazySingleton
{
public:
static inline T& reference();
static inline T* pointer();
static inline T* instance();
protected:
inline LazySingleton();
virtual inline ~LazySingleton();
private:
LazySingleton(const LazySingleton<T>&); // no copy ctor
const LazySingleton<T>& operator= (const LazySingleton<T>&); // no copy assignment
private:
static std::auto_ptr<T> theObject;
};
template<class T, class I>
std::auto_ptr<T> LazySingleton<T, I>::theObject(0);
template<class T, class I>
inline T&
LazySingleton<T, I>::reference()
{
lazySingletonTrace();
return *instance();
}
template<class T, class I>
inline T*
LazySingleton<T, I>::pointer()
{
lazySingletonTrace();
return theObject.get();
}
template<class T, class I>
inline T*
LazySingleton<T, I>::instance()
{
lazySingletonTrace();
if(!theObject.get())
{
//theObject = std::auto_ptr<T>(create<T>());
theObject = std::auto_ptr<T>(I::instantiate());
}
return theObject.get();
}
template <class T, class I>
inline
LazySingleton<T, I>::LazySingleton()
{
lazySingletonTrace();
}
template <class T, class I>
inline
LazySingleton<T, I>::~LazySingleton()
{
lazySingletonTrace();
}
}
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