XDF_CLOSEST_TYPE(3)					     xdffileio library manual					       XDF_CLOSEST_TYPE(3)

NAME

       xdf_closest_type - Returns a compatible data type

SYNOPSIS

       #include <xdfio.h>

       int xdf_closest_type(struct xdf* xdf, enum xdftype target);

DESCRIPTION

       xdf_closest_type()  selects  among  the data types supported by the file referenced by xdf the type that is the closest to the target argu-
       ment. The selected type can then be safely used in a call to xdf_set_chconf(3) with the XDF_CF_STOTYPE field.

       The selection algorithm is based on the 3  following  criterions  (cited  by  priority,	i.e.  most  important  cited  first):  data  size,
       signed/unsigned	type,  float/integer value. The data size criterion forces the selected type to have a data size (number of byte to repre-
       sent the value) equal or bigger than the one of the target type (with a preference with sizes the closest  to  the  size  of  target).  The
       signed/unsigned	criterion  tries  to  select  a type that has the same signeness (signed or unsigned data type) as the target. Finally the
       float/integer criterion tries to select a floating point type if target is float or double or an integer data type if target is an  integer
       type.

       As a consequence, if target is supported by the underlying file format of xdf, the function is ensured to return target.

RETURN VALUE

       xdf_closest_type() returns the selected data type in case of success, otherwise -1 and errno is set appropriately.

ERRORS

       EINVAL the xdf pointer is NULL, or the argument type is not an admissible enum xdftype value.

SEE ALSO

       xdf_set_chconf(3)

EPFL
								       2010						       XDF_CLOSEST_TYPE(3)