Struct LastErrorSlot 

pub struct LastErrorSlot { /* private fields */ }

The last failure recorded on this thread, and its classification.

Place one in a thread_local! in your own crate — see the module docs for why this crate does not own it.

Implementations

impl LastErrorSlot

pub const fn new() -> Self

An empty slot: no message, kind kind::NONE.

const so it can be used in thread_local! { static X: _ = const { .. } }, which avoids the lazy-initialisation check on every access.

pub fn set(&self, kind: c_int, message: &str)

Record a failure, replacing whatever was there.

A message holding an interior NUL cannot become a C string; the kind is still recorded and the message is dropped, so the caller gets a classification and a null message rather than a classification paired with the previous message.

pub fn set_error(&self, error: &FfiError)

Record a failure from an FfiError.

pub fn clear(&self)

Forget any recorded failure. Call on entry to an operation that succeeded, so a caller polling the slot does not see an old failure attributed to a new call.

pub fn message_ptr(&self) -> *const c_char

The recorded message as a C string, or null when none is recorded.

Safety of the returned pointer

Borrowed from thread-local storage: valid until the next call that writes this slot on the same thread. Callers across the ABI must copy it, not retain it. The pointer is produced inside the borrow and no reference escapes, so the value cannot be freed while a caller is still inside the same call.

pub fn kind(&self) -> c_int

The recorded classification, or kind::NONE when the last call succeeded.

Trait Implementations

impl Debug for LastErrorSlot

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

Formats the value using the given formatter.

impl Default for LastErrorSlot

fn default() -> Self

Returns the “default value” for a type.