Struct Topic 

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

A validated, borrowed MQTT topic name.

Topic names are used in PUBLISH packets to identify the subject of a message. They must not contain wildcard characters (+, #), must not be empty, and must satisfy the MqttStr constraints (≤ 65 535 bytes, no U+0000).

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

Tuple Fields

0: MqttStr

Implementations

impl Topic

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

Create a topic name without validating topic-specific invariants.

Safety

The caller must guarantee that s satisfies the topic name invariants: non-empty, no wildcard characters (+, #), and valid MqttStr.

pub const fn new(s: &MqttStr) -> Result<&Self, TopicError>

Validate and create a new topic name from a validated MqttStr.

This only checks non-empty and no wildcard characters; MqttStr guarantees length and null-character constraints.

Errors

Returns TopicError if the string is empty or contains wildcard characters (+, #).

pub const fn as_mqtt_str(&self) -> &MqttStr

View the topic as an MqttStr.

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

View the topic as a string slice.

Trait Implementations

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<Topic> for TopicBuf

Available on crate feature alloc only.

fn as_ref(&self) -> &Topic

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

impl AsRef<str> for Topic

fn as_ref(&self) -> &str

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

impl Borrow<Topic> for TopicBuf

Available on crate feature alloc only.

fn borrow(&self) -> &Topic

Immutably borrows from an owned value.

impl Debug for Topic

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

Formats the value using the given formatter.

impl Display for Topic

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

Formats the value using the given formatter.

impl From<&Topic> for TopicBuf

Available on crate feature alloc only.

fn from(value: &Topic) -> Self

Converts to this type from the input type.

impl Hash for Topic

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

Feeds this value into the given Hasher.

impl PartialEq for Topic

fn eq(&self, other: &Topic) -> 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 ToOwned for Topic

Available on crate feature alloc only.

type Owned = TopicBuf

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 Topic

type Error = ParseTopicError

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 Topic

impl StructuralPartialEq for Topic