Trait WithPrecision 

pub trait WithPrecision: BitsPrecision {
    // Required method
    fn widen_to_precision(self, bits_precision: u32) -> Self;

    // Provided methods
    fn zero_with_precision(bits_precision: u32) -> Self
       where Self: Zero { ... }
    fn one_with_precision(bits_precision: u32) -> Self
       where Self: One { ... }
    fn widen_to_precision_of(self, witness: &Self) -> Self { ... }
    fn zero_with_precision_of(witness: &Self) -> Self
       where Self: Zero { ... }
    fn one_with_precision_of(witness: &Self) -> Self
       where Self: One { ... }
}

Establishes a value’s operating width from a witness — the constructive companion to BitsPrecision. Method names mirror crypto-bigint’s BoxedUint::{zero_with_precision, one_with_precision, widen}.

Why it exists: Zero::zero/One::one are minimal-width on a runtime-width carrier, so a reducer seeded with zero() and grown toward a modulus width operates at the seed width and wraps early — correct on a fixed-width type, silently truncated on a variable-width one. T::zero_with_precision_of(&m) seeds at the modulus width instead.

widen_to_precision grows, never shrinks, and preserves the value (identity on a fixed-width carrier). It preserves value only to a representation-compatible width — a fixed-point carrier’s fractional format must match — which is why the _of forms take a witness value, not a bit count. Those forms borrow the witness, so they carry no Copy bound and serve Clone-only carriers, the case the family exists for.

use const_num_traits::WithPrecision;

// Fixed-width: width is the type; the requested precision is ignored.
assert_eq!(WithPrecision::widen_to_precision(5u32, 256), 5u32);
assert_eq!(WithPrecision::zero_with_precision_of(&99u32), 0u32);
let one: u32 = WithPrecision::one_with_precision(128);
assert_eq!(one, 1);

Required Methods

fn widen_to_precision(self, bits_precision: u32) -> Self

Returns self re-represented over a width of at least bits_precision, preserving its numeric value. Never shrinks; on a fixed-width carrier the width is the type and this is the identity.

Provided Methods

fn zero_with_precision(bits_precision: u32) -> Self

where Self: Zero,

A Zero carried at a width of at least bits_precision.

fn one_with_precision(bits_precision: u32) -> Self

where Self: One,

A One carried at a width of at least bits_precision.

fn widen_to_precision_of(self, witness: &Self) -> Self

widen_to_precision to the width of a witness value — typically the modulus a reducer operates over. Prefer this to hand-picking a bit count: the witness carries the intended width.

fn zero_with_precision_of(witness: &Self) -> Self

where Self: Zero,

A Zero carried at the witness’s width — the width-safe seed for a generic accumulator.

fn one_with_precision_of(witness: &Self) -> Self

where Self: One,

A One carried at the witness’s width.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl WithPrecision for i8

fn widen_to_precision(self, _bits_precision: u32) -> i8

impl WithPrecision for i16

fn widen_to_precision(self, _bits_precision: u32) -> i16

impl WithPrecision for i32

fn widen_to_precision(self, _bits_precision: u32) -> i32

impl WithPrecision for i64

fn widen_to_precision(self, _bits_precision: u32) -> i64

impl WithPrecision for i128

fn widen_to_precision(self, _bits_precision: u32) -> i128

impl WithPrecision for isize

fn widen_to_precision(self, _bits_precision: u32) -> isize

impl WithPrecision for u8

fn widen_to_precision(self, _bits_precision: u32) -> u8

impl WithPrecision for u16

fn widen_to_precision(self, _bits_precision: u32) -> u16

impl WithPrecision for u32

fn widen_to_precision(self, _bits_precision: u32) -> u32

impl WithPrecision for u64

fn widen_to_precision(self, _bits_precision: u32) -> u64

impl WithPrecision for u128

fn widen_to_precision(self, _bits_precision: u32) -> u128

impl WithPrecision for usize

fn widen_to_precision(self, _bits_precision: u32) -> usize

Implementors