Struct VarInt 

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

An integer less than 2^62

Values of this type are suitable for encoding as QUIC variable-length integer. It would be neat if we could express to Rust that the top two bits are available for use as enum discriminants

Implementations

impl VarInt

pub const MAX: Self

The largest possible value.

pub const ZERO: Self

The smallest possible value.

pub const fn from_u32(x: u32) -> Self

Construct a VarInt infallibly using the largest available type. Larger values need to use try_from instead.

pub const fn from_u64(x: u64) -> Option<Self>

Construct from a u64, or None if it exceeds Self::MAX.

pub const fn from_u128(x: u128) -> Option<Self>

Construct from a u128, or None if it exceeds Self::MAX.

pub const fn into_inner(self) -> u64

Extract the integer value

pub const fn from_zigzag(signed: i64) -> Result<Self, BoundsExceeded>

Encode a signed i64 as a zigzag-then-unsigned varint: (n << 1) ^ (n >> 63).

Small negative numbers map to small unsigneds (-1 -> 1, 1 -> 2, -2 -> 3, …). Returns BoundsExceeded if signed is outside [-2^61, 2^61 - 1], since the zigzag-encoded result must fit in a 62-bit varint.

pub const fn to_zigzag(self) -> i64

Decode this varint as a signed i64 via the inverse zigzag transform.

impl VarInt

pub fn decode_quic<R: Buf>(r: &mut R) -> Result<Self, DecodeError>

Decode a QUIC-style varint (2-bit length tag in top bits).

pub fn encode_quic<W: BufMut>(&self, w: &mut W) -> Result<(), EncodeError>

Encode a QUIC-style varint (2-bit length tag in top bits).

Trait Implementations

impl Clone for VarInt

fn clone(&self) -> VarInt

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for VarInt

impl Debug for VarInt

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

Formats the value using the given formatter.

impl Default for VarInt

fn default() -> VarInt

Returns the “default value” for a type.

impl Display for VarInt

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

Formats the value using the given formatter.

impl Eq for VarInt

impl From<VarInt> for u64

fn from(x: VarInt) -> Self

Converts to this type from the input type.

impl From<VarInt> for usize

fn from(x: VarInt) -> Self

Converts to this type from the input type.

impl From<VarInt> for u128

fn from(x: VarInt) -> Self

Converts to this type from the input type.

impl From<u8> for VarInt

fn from(x: u8) -> Self

Converts to this type from the input type.

impl From<u16> for VarInt

fn from(x: u16) -> Self

Converts to this type from the input type.

impl From<u32> for VarInt

fn from(x: u32) -> Self

Converts to this type from the input type.

impl Hash for VarInt

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for VarInt

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

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for VarInt

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for VarInt

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl StructuralPartialEq for VarInt

impl TryFrom<VarInt> for u32

fn try_from(x: VarInt) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^32

type Error = BoundsExceeded

The type returned in the event of a conversion error.

impl TryFrom<VarInt> for u16

fn try_from(x: VarInt) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^16

type Error = BoundsExceeded

The type returned in the event of a conversion error.

impl TryFrom<VarInt> for u8

fn try_from(x: VarInt) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^8

type Error = BoundsExceeded

The type returned in the event of a conversion error.

impl TryFrom<u64> for VarInt

fn try_from(x: u64) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^62

type Error = BoundsExceeded

The type returned in the event of a conversion error.

impl TryFrom<u128> for VarInt

fn try_from(x: u128) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^62

type Error = BoundsExceeded

The type returned in the event of a conversion error.

impl TryFrom<usize> for VarInt

fn try_from(x: usize) -> Result<Self, BoundsExceeded>

Succeeds iff x < 2^62

type Error = BoundsExceeded

The type returned in the event of a conversion error.