Struct HexSignificand 

pub struct HexSignificand { /* private fields */ }

A C99 hex float’s significand, accumulated exactly.

The value is m * 2^e2, plus a non-zero tail below m’s window when sticky is set. m holds up to 60 bits, well past f64’s 53 plus the guard and round bits, so the sticky tail is all the rounding needs.

Implementations

impl HexSignificand

pub fn new() -> Self

pub fn push_digit(&mut self, digit: u8, fractional: bool)

Fold in one hex digit. fractional marks the digits after the ., which lower the exponent instead of raising the value.

pub fn apply_binary_exponent(&mut self, exp: i32)

Apply the p<exp> binary exponent.

pub fn to_f64(&self) -> (f64, bool)

Round to the nearest f64 (ties to even) and report errno == ERANGE.

glibc sets ERANGE when the result overflows to infinity, and when the EXACT value is tiny (below the smallest normal, 2^-1022) and the conversion is inexact. Note both halves: 0x1p-1074 is tiny but exact (no ERANGE), and 0x1.fffffffffffffp-1023 is tiny-and-inexact yet rounds up to the smallest normal — ERANGE all the same, because the test is on the value before rounding.

Trait Implementations

impl Clone for HexSignificand

fn clone(&self) -> HexSignificand

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for HexSignificand

impl Debug for HexSignificand

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for HexSignificand

fn default() -> HexSignificand

Returns the “default value” for a type.