Function RB_FIXABLE

pub fn RB_FIXABLE<T: Fixable>(x: T) -> bool

Check whether the given numeric is in the range of fixnum.

RB_FIXABLE can be applied to any numeric type. See the implementers of the Fixable trait for more details on which numeric types are fixable.

To convert the given numeric value to a fixnum instead, see Fixable::to_fix.

Examples

use scolapasta_fixable::RB_FIXABLE;

assert!(RB_FIXABLE(23_u8));
assert!(RB_FIXABLE(u16::MIN));
assert!(RB_FIXABLE(i32::MAX));
assert!(RB_FIXABLE(1024_u64));
assert!(RB_FIXABLE(1024_i64));
assert!(RB_FIXABLE(1.0_f32));
assert!(RB_FIXABLE(-9000.27_f64));

C Declaration

/**
 * Checks if the passed value is in  range of fixnum, assuming it is a positive
 * number.  Can sometimes be useful for C's unsigned integer types.
 *
 * @internal
 *
 * FIXABLE can be applied to anything, from double to intmax_t.  The problem is
 * double.   On a  64bit system  RUBY_FIXNUM_MAX is  4,611,686,018,427,387,903,
 * which is not representable by a double.  The nearest value that a double can
 * represent  is   4,611,686,018,427,387,904,  which   is  not   fixable.   The
 * seemingly-strange "< FIXNUM_MAX + 1" expression below is due to this.
 */
#define RB_POSFIXABLE(_) ((_) <  RUBY_FIXNUM_MAX + 1)

/**
 * Checks if the passed value is in  range of fixnum, assuming it is a negative
 * number.  This is an implementation of #RB_FIXABLE.  Rarely used stand alone.
 */
#define RB_NEGFIXABLE(_) ((_) >= RUBY_FIXNUM_MIN)

/** Checks if the passed value is in  range of fixnum */
#define RB_FIXABLE(_)    (RB_POSFIXABLE(_) && RB_NEGFIXABLE(_))