Struct actix_web::http::header::Quality

pub struct Quality(/* private fields */);

Represents a quality used in q-factor values.

The default value is equivalent to q=1.0 (the max value).

Implementation notes

The quality value is defined as a number between 0.0 and 1.0 with three decimal places. This means there are 1001 possible values. Since floating point numbers are not exact and the smallest floating point data type (f32) consumes four bytes, we use an u16 value to store the quality internally.

RFC 7231 §5.3.1 gives more information on quality values in HTTP header fields.

Examples

use actix_http::header::{Quality, q};
assert_eq!(q(1.0), Quality::MAX);

assert_eq!(q(0.42).to_string(), "0.42");
assert_eq!(q(1.0).to_string(), "1");
assert_eq!(Quality::MIN.to_string(), "0.001");
assert_eq!(Quality::ZERO.to_string(), "0");

Implementations

impl Quality

pub const MAX: Quality = _

The maximum quality value, equivalent to q=1.0.

pub const MIN: Quality = _

The minimum, non-zero quality value, equivalent to q=0.001.

pub const ZERO: Quality = _

The zero quality value, equivalent to q=0.0.

Trait Implementations

impl Clone for Quality

fn clone(&self) -> Quality

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Quality

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

Formats the value using the given formatter.

impl Default for Quality

The default value is Quality::MAX.

fn default() -> Quality

Returns the “default value” for a type.

impl Display for Quality

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

Formats the value using the given formatter.

impl Ord for Quality

fn cmp(&self, other: &Quality) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<Quality> for Quality

fn eq(&self, other: &Quality) -> 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<Quality> for Quality

fn partial_cmp(&self, other: &Quality) -> 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 TryFrom<f32> for Quality

type Error = QualityOutOfBounds

The type returned in the event of a conversion error.

fn try_from(value: f32) -> Result<Quality, <Quality as TryFrom<f32>>::Error>

Performs the conversion.

impl Copy for Quality

impl Eq for Quality

impl StructuralEq for Quality

impl StructuralPartialEq for Quality