windows-nt/Source/XPSP1/NT/enduser/troubleshoot/bn/dyncast.h

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2020-09-26 03:20:57 -05:00
//+-------------------------------------------------------------------------
//
// Microsoft Windows
//
// Copyright (C) Microsoft Corporation, 1997 - 1997
//
// File: dyncast.h
//
//--------------------------------------------------------------------------
//
// dyncast.h: Handle dynamic and static casting
//
#ifndef _DYNCAST_H_
#define _DYNCAST_H_
// Macro to perform const_cast; i.e., cast away "const-ness" without
// changing base type.
#define CONST_CAST(type,arg) const_cast<type>(arg)
//
// Function templates for generating error-detecting dynamic casts.
// The compiler will generate the needed version of this based upon the types
// provided. 'DynCastThrow' should be used when you're certain of the
// type of an object. 'PdynCast" should be used when you intend to check
// whether the conversion was successful (result != NULL).
// If 'USE_STATIC_CAST' is defined, static casting is done in DynCastThrow().
//
//#define USE_STATIC_CAST // Uncomment to force static casting
//#define TIME_DYN_CASTS // Uncomment to generate timing information
template <class BASE, class SUB>
void DynCastThrow ( BASE * pbase, SUB * & psub )
{
#ifdef TIME_DYN_CASTS
extern int g_cDynCasts;
g_cDynCasts++;
#endif
#if defined(USE_STATIC_CAST) && !defined(_DEBUG)
psub = (SUB *) pbase;
#else
psub = dynamic_cast<SUB *>(pbase);
ASSERT_THROW( psub, EC_DYN_CAST,"subclass pointer conversion failure");
#endif
}
template <class BASE, class SUB>
SUB * PdynCast ( BASE * pbase, SUB * psub )
{
return dynamic_cast<SUB *>(pbase);
}
#endif // _DYNCAST_H_