Struct MqttStr 

#[repr(transparent)]
pub struct MqttStr(str);

A UTF-8 string that satisfies all MQTT v5 requirements:

• Well-formed UTF-8 (guaranteed by Rust’s str)
• No surrogate code points U+D800..U+DFFF (guaranteed by Rust’s str)
• No null character U+0000 [MQTT-1.5.4-2]
• At most 65 535 bytes

This is an unsized type like str. Use &MqttStr for borrowed references and MqttString for owned values.

Tuple Fields

0: str

Implementations

impl MqttStr

pub const EMPTY: &'static Self

The empty MQTT string.

pub const unsafe fn new_unchecked(s: &str) -> &Self

Creates a new MQTT string without validating MQTT-specific invariants.

Safety

The caller must guarantee that s satisfies the MQTT string invariants.

pub const fn new(s: &str) -> Result<&Self, DataError>

Validates and wraps a &str.

Errors

Returns DataError::TooLong if s exceeds 65 535 bytes, or DataError::ContainsNull if s contains U+0000.

pub(crate) const fn contains_null(bytes: &[u8]) -> bool

Whether bytes contains the null character U+0000, forbidden by [MQTT-1.5.4-2]. In valid UTF-8 the null character is always exactly the single byte 0x00, so a byte scan is correct.

Exposed separately from new for a caller that already knows the length invariant holds, e.g. after reading a length-prefixed field off the wire, so it does not have to re-check a bound it already enforced.

pub const fn as_mqtt_bytes(&self) -> &MqttBytes

Returns this string as MqttBytes.

pub const fn as_str(&self) -> &str

Returns the underlying &str.

pub const fn len(&self) -> usize

Returns the length in bytes.

pub const fn len_u16(&self) -> u16

Returns the length as a u16 for encoding.

pub const fn encoded_len(&self) -> usize

Returns the number of bytes needed to encode this value.

pub const fn is_empty(&self) -> bool

Returns true if the string is empty.

pub const fn as_bytes(&self) -> &[u8]

Returns the raw UTF-8 bytes.

Trait Implementations

impl AsRef<MqttStr> for MqttString

Available on crate feature alloc only.

fn as_ref(&self) -> &MqttStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MqttStr> for Topic

fn as_ref(&self) -> &MqttStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MqttStr> for TopicBuf

Available on crate feature alloc only.

fn as_ref(&self) -> &MqttStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MqttStr> for TopicFilter

fn as_ref(&self) -> &MqttStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MqttStr> for TopicFilterBuf

Available on crate feature alloc only.

fn as_ref(&self) -> &MqttStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<str> for MqttStr

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<MqttStr> for MqttString

Available on crate feature alloc only.

fn borrow(&self) -> &MqttStr

Immutably borrows from an owned value.

impl Debug for MqttStr

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

Formats the value using the given formatter.

impl Display for MqttStr

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

Formats the value using the given formatter.

impl Hash for MqttStr

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

Feeds this value into the given Hasher.

impl Ord for MqttStr

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

This method returns an Ordering between self and other.

impl PartialEq for MqttStr

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for MqttStr

fn partial_cmp(&self, other: &MqttStr) -> 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 ToOwned for MqttStr

Available on crate feature alloc only.

type Owned = MqttString

The resulting type after obtaining ownership.

fn to_owned(&self) -> Self::Owned

Creates owned data from borrowed data, usually by cloning.

fn clone_into(&self, target: &mut Self::Owned)

Uses borrowed data to replace owned data, usually by cloning.

impl<'a> TryFrom<&'a str> for &'a MqttStr

type Error = DataError

The type returned in the event of a conversion error.

fn try_from(value: &'a str) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for MqttStr

impl StructuralPartialEq for MqttStr