Struct rug::float::MiniFloat

pub struct MiniFloat { /* private fields */ }

A small float that does not require any memory allocation.

This can be useful when you have a primitive number type but need a reference to a Float. The MiniFloat will have a precision according to the type of the primitive used to set its value.

• i8, u8: the MiniFloat will have eight bits of precision.
• i16, u16: the MiniFloat will have 16 bits of precision.
• i32, u32: the MiniFloat will have 32 bits of precision.
• i64, u64: the MiniFloat will have 64 bits of precision.
• i128, u128: the MiniFloat will have 128 bits of precision.
• isize, usize: the MiniFloat will have 32 or 64 bits of precision, depending on the platform.
• f32: the MiniFloat will have 24 bits of precision.
• f64: the MiniFloat will have 53 bits of precision.
• Special: the MiniFloat will have the minimum possible precision.

The borrow method returns an object that can be coerced to a Float, as it implements Deref<Target = Float>.

Examples

use rug::float::MiniFloat;
use rug::Float;
// `a` requires a heap allocation, has 53-bit precision
let mut a = Float::with_val(53, 250);
// `b` can reside on the stack
let b = MiniFloat::from(-100f64);
a += &*b.borrow();
assert_eq!(a, 150);
// another computation:
a *= &*b.borrow();
assert_eq!(a, -15000);

Implementations

impl MiniFloat

pub const fn new() -> Self

Creates a MiniFloat with value 0 and the minimum possible precision.

Examples

use rug::float::MiniFloat;
let f = MiniFloat::new();
// Borrow f as if it were Float.
assert_eq!(*f.borrow(), 0);

pub unsafe fn as_nonreallocating_float(&mut self) -> &mut Float

Returns a mutable reference to a Float for simple operations that do not need to change the precision of the number.

Safety

It is undefined behavior modify the precision of the referenced Float or to swap it with another number.

Examples

use rug::float::MiniFloat;
let mut f = MiniFloat::from(1.0f32);
// addition does not change the precision
unsafe {
    *f.as_nonreallocating_float() += 2.0;
}
assert_eq!(*f.borrow(), 3.0);

pub fn borrow(&self) -> impl Deref<Target = Float> + '_

Borrows the floating-point number.

The returned object implements Deref<Target = Float>.

The borrow lasts until the returned object exits scope. Multiple borrows can be taken at the same time.

Examples

use rug::float::MiniFloat;
use rug::Float;
let f = MiniFloat::from(-13i32);
let b = f.borrow();
let abs_ref = b.abs_ref();
assert_eq!(Float::with_val(53, abs_ref), 13);

pub fn borrow_excl(&mut self) -> &Float

Borrows the floating-point number exclusively.

This is similar to the borrow method, but it requires exclusive access to the underlying MiniFloat; the returned reference can however be shared. The exclusive access is required to reduce the amount of housekeeping necessary, providing a more efficient operation.

Examples

use rug::float::MiniFloat;
use rug::Float;
let mut f = MiniFloat::from(-13i32);
let b = f.borrow_excl();
let abs_ref = b.abs_ref();
assert_eq!(Float::with_val(53, abs_ref), 13);

Trait Implementations

impl Assign<&MiniFloat> for MiniFloat

fn assign(&mut self, other: &Self)

Peforms the assignement.

impl<T: ToMini> Assign<T> for MiniFloat

fn assign(&mut self, src: T)

Peforms the assignement.

impl Assign for MiniFloat

fn assign(&mut self, other: Self)

Peforms the assignement.

impl AssignRound<&MiniFloat> for Float

type Round = Round

The rounding method.

type Ordering = Ordering

The direction from rounding.

fn assign_round(&mut self, src: &MiniFloat, round: Round) -> Ordering

Peforms the assignment.

impl AssignRound<MiniFloat> for Float

type Round = Round

The rounding method.

type Ordering = Ordering

The direction from rounding.

fn assign_round(&mut self, src: MiniFloat, round: Round) -> Ordering

Peforms the assignment.

impl Binary for MiniFloat

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

Formats the value using the given formatter.

impl Clone for MiniFloat

fn clone(&self) -> MiniFloat

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MiniFloat

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

Formats the value using the given formatter.

impl Default for MiniFloat

fn default() -> Self

Returns the “default value” for a type.

impl Display for MiniFloat

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

Formats the value using the given formatter.

impl<T: ToMini> From<T> for MiniFloat

fn from(src: T) -> Self

Converts to this type from the input type.

impl LowerExp for MiniFloat

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

Formats the value using the given formatter.

impl LowerHex for MiniFloat

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

Formats the value using the given formatter.

impl Octal for MiniFloat

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

Formats the value using the given formatter.

impl PartialEq<Float> for MiniFloat

fn eq(&self, other: &Float) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<MiniFloat> for Float

fn eq(&self, other: &MiniFloat) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<Float> for MiniFloat

fn partial_cmp(&self, other: &Float) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<MiniFloat> for Float

fn partial_cmp(&self, other: &MiniFloat) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl UpperExp for MiniFloat

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

Formats the value using the given formatter.

impl UpperHex for MiniFloat

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

Formats the value using the given formatter.

impl Copy for MiniFloat

impl Send for MiniFloat

impl Sync for MiniFloat