Struct TryWriteError

pub struct TryWriteError { /* private fields */ }

An error that occurs when trying to write data to a buffer with insufficient space.

This error indicates that a write operation failed because the buffer does not have enough remaining capacity to hold the data.

This error is particularly useful for Sans-I/O designs as it provides exact information about space requirements, allowing the caller to allocate a larger buffer and retry:

let mut small_buf = [0u8; 4];
let mut writer = &mut small_buf[..];

match writer.try_write_u64_le(0x123456789ABCDEF0) {
    Err(e) => {
        // Caller knows exactly how much space is needed
        assert_eq!(e.requested(), 8);
        assert_eq!(e.available(), 4);
        println!("Need {} more bytes", e.shortage());
    }
    _ => panic!("Expected error"),
}

Implementations

impl TryWriteError

pub const fn new(requested: usize, available: usize) -> Self

Creates a new TryWriteError with the requested and available bytes.

Panics

• In debug builds, panics if requested <= available (this would not be an error condition).
• The requested value must be a non-zero.

pub const fn requested(&self) -> usize

Returns the number of bytes requested for the operation.

This is the minimum number of bytes needed for the operation to succeed.

pub const fn available(&self) -> usize

Returns the number of bytes available in the buffer.

This is the actual number of bytes that were available when the operation failed.

pub const fn shortage(&self) -> usize

Returns the number of additional bytes needed for the operation to succeed.

This is equivalent to requested() - available().

Trait Implementations

impl Clone for TryWriteError

fn clone(&self) -> TryWriteError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TryWriteError

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

Formats the value using the given formatter.

impl Display for TryWriteError

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

Formats the value using the given formatter.

impl Error for TryWriteError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<TryWriteError> for Error

fn from(e: TryWriteError) -> Self

Converts to this type from the input type.

impl PartialEq for TryWriteError

fn eq(&self, other: &TryWriteError) -> 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 Copy for TryWriteError

impl Eq for TryWriteError

impl StructuralPartialEq for TryWriteError