ieeefp.h

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//
//
/*
    Copyright (C) 2004- 2012, Hammersmith Imanet Ltd
    This file is part of STIR.

    SPDX-License-Identifier: Apache-2.0

    See STIR/LICENSE.txt for details
*/
#ifndef __stir_numerics_ieeefp_H__
#define __stir_numerics_ieeefp_H__

#include "stir/common.h"

#if defined(_MSC_VER)

#  include <float.h>
#  define STIR_isnan _isnan
#  define STIR_finite _finite

#else

#  include <cmath>

// attempt to get to find isnan but it might not work on some systems
// terrible hack to try and find isnan in std
// will only work for gcc
#  if _GLIBCPP_USE_C99 && !_GLIBCPP_USE_C99_FP_MACROS_DYNAMIC
#    define STIR_isnan std::isnan
#    define STIR_finite std::isfinite
#  else
#    if defined(HAVE_IEEEFP_H) // this macro might be set (but probably only by configure)
#      include <ieeefp.h>
#      define STIR_isnan isnan
#      define STIR_finite finite
#    endif
#  endif

#endif

#if !defined(STIR_isnan)
#  if defined(isnan)
#    define STIR_isnan isnan
#  else // portable version
// according to IEEE rules if x is NaN, then x!=x
// so, the following will work even on non-IEEE systems
#    define STIR_isnan(x) (x) != (x)
#  endif
#endif

#if !defined(STIR_finite)
#  if defined(finite)
#    define STIR_finite finite
#  else // portable version
// we give up and say all numbers are finite
#    define STIR_finite(x) true
#  endif
#endif

#ifdef DOXYGEN_SKIP // only when running doxygen
// doxygen doesn't execute above preprocessor commands, but then doesn't generate documentation
// so define something here
#  define STIR_finite finite
#  define STIR_isnan isnan
#endif

#endif