eb5bcb8eaf
The local typedef used for type checking is unreferenced, and causes spurious warning with GCC 4.8. Use an inline std::enable_if return type munging to elide template instantiations for unrelated types. Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
65 lines
1.7 KiB
C++
65 lines
1.7 KiB
C++
/* vim: set sw=4 sts=4 et foldmethod=syntax : */
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/*
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* Copyright (c) 2008, 2009, 2010, 2011 Ciaran McCreesh
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*
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* This file is part of the Paludis package manager. Paludis is free software;
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* you can redistribute it and/or modify it under the terms of the GNU General
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* Public License version 2, as published by the Free Software Foundation.
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*
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* Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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* Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef PALUDIS_GUARD_PALUDIS_UTIL_VISITOR_CAST_HH
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#define PALUDIS_GUARD_PALUDIS_UTIL_VISITOR_CAST_HH 1
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#include <paludis/util/visitor_cast-fwd.hh>
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#include <paludis/util/visitor.hh>
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#include <type_traits>
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namespace paludis
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{
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template <typename To_, typename From_>
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struct VisitorCaster
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{
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To_ * visit(To_ & t)
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{
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return &t;
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}
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To_ * visit(From_ &)
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{
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return 0;
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}
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};
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template <typename C_, typename T_>
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struct CopyConst
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{
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typedef T_ Type;
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};
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template <typename C_, typename T_>
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struct CopyConst<const C_, T_>
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{
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typedef const T_ Type;
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};
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template <typename To_, typename From_, typename>
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To_ *
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visitor_cast(From_ & from)
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{
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VisitorCaster<To_, typename CopyConst<From_, typename From_::VisitableBaseClass>::Type> q;
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return from.template accept_returning<To_ *>(q);
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}
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}
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#endif
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