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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
namespace detail
{
template<typename T>
struct has_clone
{
template<typename U, U x>
struct test;
typedef char yes;
typedef struct { char a[2]; } no;
template<typename U>
static yes& check_sig(U*, test<U* (U::*)() const, &U::clone>* = 0);
template<typename U>
static no& check_sig(...);
enum
{
value = sizeof(check_sig<T>(0)) == sizeof(yes)
};
};
template<typename T, bool HasClone>
struct cloner
{
static T* clone(T* const other)
{
return new T(*other);
}
};
template<typename T>
struct cloner<T, true>
{
static T* clone(T* const other)
{
return other->clone();
}
};
}
/** Creates a new copy of the passed object.
If other is 0, just returns 0. Otherwise, if other has function
named clone with signature T* (T::*)() const, the function is called.
Otherwise, copy constructor is used.
@returns 0 or newly allocated object
*/
template<typename T>
T* clone(T* const other)
{
return other ? ::detail::cloner<T, ::detail::has_clone<T>::value>::clone(other) : 0;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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