Struct dec::Decimal

#[repr(C)]pub struct Decimal<const N: usize> { /* fields omitted */ }

This is supported on crate feature arbitrary-precision only.

An arbitrary-precision decimal number.

The maximum number of digits that can be stored in the number is specified by N * 3. For example, a value of type Decimal<3> has space for nine decimal digits. This somewhat odd design is due to limitations of constant generic parameters in Rust. The intention is to someday make N correspond directly to the number of digits of precision.

N must be at least 12 and no greater than 999,999,999, though typically the stack size implies a smaller maximum for N. Due to limitations with constant generics it is not yet possible to enforce these restrictions at compile time, so they are checked at runtime.

Implementations

impl<const N: usize> Decimal<N>

pub fn zero() -> Decimal<N>

Constructs a decimal number with N / 3 digits of precision representing the number 0.

pub fn digits(&self) -> u32

Computes the number of significant digits in the number.

If the number is zero or infinite, returns 1. If the number is a NaN, returns the number of digits in the payload.

pub fn exponent(&self) -> i32

Computes the exponent of the number.

pub fn is_finite(&self) -> bool

Reports whether the number is finite.

A finite number is one that is neither infinite nor a NaN.

pub fn is_infinite(&self) -> bool

Reports whether the number is positive or negative infinity.

pub fn is_nan(&self) -> bool

Reports whether the number is a NaN.

pub fn is_negative(&self) -> bool

Reports whether the number is negative.

A negative number is either negative zero, less than zero, or NaN with a sign of one. This corresponds to Decimal128::is_signed, not Decimal128::is_negative.

pub fn is_quiet_nan(&self) -> bool

Reports whether the number is a quiet NaN.

pub fn is_signaling_nan(&self) -> bool

Reports whether the number is a signaling NaN.

pub fn is_special(&self) -> bool

Reports whether the number has a special value.

A special value is either infinity or NaN. This is the inverse of Decimal::is_finite.

pub fn is_zero(&self) -> bool

Reports whether the number is positive or negative zero.

pub fn quantum_matches(&self, rhs: &Decimal<N>) -> bool

Reports whether the quantum of the number matches the quantum of rhs.

Quantums are considered to match if the numbers have the same exponent, are both NaNs, or both infinite.

pub fn to_decimal32(&self) -> Decimal32

Converts this decimal to a 32-bit decimal float.

The result may be inexact. Use Context::<Decimal32>::from_decimal to observe exceptional conditions.

pub fn to_decimal64(&self) -> Decimal64

Converts this decimal to a 64-bit decimal float.

The result may be inexact. Use Context::<Decimal64>::from_decimal to observe exceptional conditions.

pub fn to_decimal128(&self) -> Decimal128

Converts this decimal to a 128-bit decimal float.

The result may be inexact. Use Context::<Decimal128>::from_decimal to observe exceptional conditions.

pub fn to_raw_parts(&self) -> (u32, i32, u8, [u16; N])

Returns the raw parts of this decimal.

The meaning of these parts are unspecified and subject to change.

Trait Implementations

impl<const N: usize> Clone for Decimal<N>

fn clone(&self) -> Decimal<N>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<const N: usize> Debug for Decimal<N>

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

Formats the value using the given formatter.

impl<const N: usize> Default for Decimal<N>

fn default() -> Decimal<N>

Returns the “default value” for a type.

impl<const N: usize> Display for Decimal<N>

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

Formats the value using the given formatter.

impl<const N: usize> From<Decimal128> for Decimal<N>

fn from(n: Decimal128) -> Decimal<N>

Performs the conversion.

impl<const N: usize> From<Decimal32> for Decimal<N>

fn from(n: Decimal32) -> Decimal<N>

Performs the conversion.

impl<const N: usize> From<Decimal64> for Decimal<N>

fn from(n: Decimal64) -> Decimal<N>

Performs the conversion.

impl<const N: usize> FromStr for Decimal<N>

type Err = ParseDecimalError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Decimal<N>, ParseDecimalError>

Parses a string s to return a value of this type.