goldendict-ng/winlibs/include/xapian/derefwrapper.h

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2022-10-05 09:50:44 +00:00
/** @file
* @brief Class for wrapping type returned by an input_iterator.
*/
/* Copyright (C) 2004,2008,2009,2013,2014 Olly Betts
*
* 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 XAPIAN_INCLUDED_DEREFWRAPPER_H
#define XAPIAN_INCLUDED_DEREFWRAPPER_H
#if !defined XAPIAN_IN_XAPIAN_H && !defined XAPIAN_LIB_BUILD
# error Never use <xapian/derefwraper.h> directly; include <xapian.h> instead.
#endif
namespace Xapian {
/** @private @internal Class which returns a value when dereferenced with
* operator*.
*
* We need this wrapper class to implement input_iterator semantics for the
* postfix operator++ methods of some of our iterator classes.
*/
template<typename T>
class DerefWrapper_ {
/// Don't allow assignment.
#if __cplusplus >= 201103L
// Avoid warnings with newer clang.
void operator=(const DerefWrapper_&) = delete;
#else
void operator=(const DerefWrapper_&);
#endif
/// The value.
T res;
public:
#if __cplusplus >= 201103L
/// Default copy constructor.
DerefWrapper_(const DerefWrapper_&) = default;
#endif
explicit DerefWrapper_(const T &res_) : res(res_) { }
const T & operator*() const { return res; }
};
}
#endif // XAPIAN_INCLUDED_DEREFWRAPPER_H