```
/* gsl_mode.h
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000, 2004 Gerard Jungman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/* Author: B. Gough and G. Jungman */
#ifndef __GSL_MODE_H__
#define __GSL_MODE_H__
#include <gsl/gsl_inline.h>
#undef __BEGIN_DECLS
#undef __END_DECLS
#ifdef __cplusplus
# define __BEGIN_DECLS extern "C" {
# define __END_DECLS }
#else
# define __BEGIN_DECLS /* empty */
# define __END_DECLS /* empty */
#endif
__BEGIN_DECLS
/* Some functions can take a mode argument. This
* is a rough method to do things like control
* the precision of the algorithm. This mainly
* occurs in special functions, but we figured
* it was ok to have a general facility.
*
* The mode type is 32-bit field. Most of
* the fields are currently unused. Users
* '|' various predefined constants to get
* a desired mode.
*/
typedef unsigned int gsl_mode_t;
/* Here are the predefined constants.
* Note that the precision constants
* are special because they are used
* to index arrays, so do not change
* them. The precision information is
* in the low order 3 bits of gsl_mode_t
* (the third bit is currently unused).
*/
/* Note that "0" is double precision,
* so that you get that by default if
* you forget a flag.
*/
#define GSL_PREC_DOUBLE 0
#define GSL_PREC_SINGLE 1
#define GSL_PREC_APPROX 2
#ifdef HAVE_INLINE
INLINE_FUN unsigned int GSL_MODE_PREC(gsl_mode_t mt);
INLINE_FUN unsigned int
GSL_MODE_PREC(gsl_mode_t mt)
{ return (mt & (unsigned int)7); }
#else /* HAVE_INLINE */
#define GSL_MODE_PREC(mt) ((mt) & (unsigned int)7)
#endif /* HAVE_INLINE */
/* Here are some predefined generic modes.
*/
#define GSL_MODE_DEFAULT 0
__END_DECLS
#endif /* __GSL_MODE_H__ */
```