GenProg.hh

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//=============================================================================
//
//  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 ===========================================================
 
 
template <bool b> struct Bool2Type { enum { my_bool = b }; };
 
template <int i>  struct Int2Type  { enum { my_int = i }; };
 
typedef Bool2Type<true> TrueType;
 
typedef Bool2Type<false> FalseType;
 
//-----------------------------------------------------------------------------
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 <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 <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
//=============================================================================