48 lines
1.2 KiB
C++
48 lines
1.2 KiB
C++
// Copyright (c) 2007,2009 INRIA Sophia-Antipolis (France). All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org)
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//
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// $URL: https://github.com/CGAL/cgal/blob/v5.1/STL_Extension/include/CGAL/Default.h $
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// $Id: Default.h 0779373 2020-03-26T13:31:46+01:00 Sébastien Loriot
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// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
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//
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// Author(s) : Sylvain Pion
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#ifndef CGAL_DEFAULT_H
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#define CGAL_DEFAULT_H
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namespace CGAL {
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// Default is a tag that can be used to shrink mangled names and
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// error messages in place of the default value of template arguments.
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// It could also be used by users to specify default values to arguments which
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// are not at the end of the argument list.
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// It can also be useful to easily break cyclic dependencies in templates.
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struct Default
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{
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template <typename Argument, typename Value>
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struct Get {
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typedef Argument type;
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};
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template <typename Value>
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struct Get <Default, Value> {
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typedef Value type;
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};
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template <typename Argument, typename Fct>
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struct Lazy_get {
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typedef Argument type;
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};
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template <typename Fct>
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struct Lazy_get <Default, Fct> {
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typedef typename Fct::type type;
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};
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};
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}
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#endif // CGAL_DEFAULT_H
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