76 lines
1.9 KiB
C++
76 lines
1.9 KiB
C++
/*
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MAYBE-COMPARE.hpp - guarded invocation of comparisons
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Copyright (C) Lumiera.org
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2009, Hermann Vosseler <Ichthyostega@web.de>
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef LIB_META_MAYBE_COMPARE_H
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#define LIB_META_MAYBE_COMPARE_H
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#include "lib/functor-util.hpp"
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#include <functional>
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namespace lib {
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namespace meta{
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using std::function;
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/**
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* Trait template for invoking equality comparison.
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* This allows to treat some types specifically....
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*/
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template<typename X>
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struct Comparator
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{
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static bool
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equals (X const& x1, X const& x2)
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{
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return x1 == x2;
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}
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};
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/** while the boost function implementation doesn't provide comparison,
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* we'll use our private hack, which at least detects equivalence
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* in \em some cases... */
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template<typename SIG>
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struct Comparator<function<SIG> >
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{
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static bool
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equals (function<SIG> const& f1, function<SIG> const& f2)
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{
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return util::rawComparison(f1,f2);
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}
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};
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template<typename X>
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inline bool
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equals_safeInvoke (X const& x1, X const& x2)
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{
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return Comparator<X>::equals(x1,x2);
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}
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}} // namespace lib::meta
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#endif
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