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openmesh/src/OpenMesh/Core/Utils/GenProg.hh
Jan Möbius f3312397a5 Updated License Headers
git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@736 fdac6126-5c0c-442c-9429-916003d36597
2012-10-08 07:30:49 +00:00

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C++

/*===========================================================================*\
* *
* OpenMesh *
* Copyright (C) 2001-2012 by Computer Graphics Group, RWTH Aachen *
* www.openmesh.org *
* *
*---------------------------------------------------------------------------*
* This file is part of OpenMesh. *
* *
* OpenMesh is free software: you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation, either version 3 of *
* the License, or (at your option) any later version with the *
* following exceptions: *
* *
* If other files instantiate templates or use macros *
* or inline functions from this file, or you compile this file and *
* link it with other files to produce an executable, this file does *
* not by itself cause the resulting executable to be covered by the *
* GNU Lesser General Public License. This exception does not however *
* invalidate any other reasons why the executable file might be *
* covered by the GNU Lesser General Public License. *
* *
* OpenMesh 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 Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU LesserGeneral Public *
* License along with OpenMesh. If not, *
* see <http://www.gnu.org/licenses/>. *
* *
\*===========================================================================*/
/*===========================================================================*\
* *
* $Revision$ *
* $Date$ *
* *
\*===========================================================================*/
//=============================================================================
//
// Utils for generic/generative programming
//
//=============================================================================
#ifndef OPENMESH_GENPROG_HH
#define OPENMESH_GENPROG_HH
//== INCLUDES =================================================================
#include <OpenMesh/Core/System/config.h>
//== NAMESPACES ===============================================================
namespace OpenMesh {
namespace GenProg {
#ifndef DOXY_IGNORE_THIS
//== IMPLEMENTATION ===========================================================
/// This type maps \c true or \c false to different types.
template <bool b> struct Bool2Type { enum { my_bool = b }; };
/// This class generates different types from different \c int 's.
template <int i> struct Int2Type { enum { my_int = i }; };
/// Handy typedef for Bool2Type<true> classes
typedef Bool2Type<true> True;
/// Handy typedef for Bool2Type<false> classes
typedef Bool2Type<false> False;
//-----------------------------------------------------------------------------
/// compile time assertions
template <bool Expr> struct AssertCompile;
template <> struct AssertCompile<true> {};
//--- Template "if" w/ partial specialization ---------------------------------
#if OM_PARTIAL_SPECIALIZATION
template <bool condition, class Then, class Else>
struct IF { typedef Then Result; };
/** Template \c IF w/ partial specialization
\code
typedef IF<bool, Then, Else>::Result ResultType;
\endcode
*/
template <class Then, class Else>
struct IF<false, Then, Else> { typedef Else Result; };
//--- Template "if" w/o partial specialization --------------------------------
#else
struct SelectThen
{
template <class Then, class Else> struct Select {
typedef Then Result;
};
};
struct SelectElse
{
template <class Then, class Else> struct Select {
typedef Else Result;
};
};
template <bool condition> struct ChooseSelector {
typedef SelectThen Result;
};
template <> struct ChooseSelector<false> {
typedef SelectElse Result;
};
/** Template \c IF w/o partial specialization. Use it like
\code
typedef IF<bool, Then, Else>::Result ResultType;
\endcode
*/
template <bool condition, class Then, class Else>
class IF
{
typedef typename ChooseSelector<condition>::Result Selector;
public:
typedef typename Selector::template Select<Then, Else>::Result Result;
};
#endif
//=============================================================================
#endif
} // namespace GenProg
} // namespace OpenMesh
#define assert_compile(EXPR) GenProg::AssertCompile<(EXPR)>();
//=============================================================================
#endif // OPENMESH_GENPROG_HH defined
//=============================================================================