Struct Retval

#[repr(C)]
pub struct Retval(/* private fields */);

System Call Return Value

On linux platforms, system calls return native integers as result. A special range is used for errors. This type wraps this result type and provides accessors to its underlying values.

Implementations

impl Retval

pub const fn from_usize(v: usize) -> Retval

Create a new return-value from raw data

pub const fn as_usize(self) -> usize

Return raw underlying data of a return-value

pub const fn is_error(self) -> bool

Check whether this is an error-return

pub const fn is_success(self) -> bool

Check whether this is a success-return

pub unsafe fn error_unchecked(self) -> usize

Return the error-code unchecked

Safety

This does not verify that self is actually an error-return. It assumes the caller verified it.

pub fn error(self) -> usize

Return the error-code

If self is not actually an error-return, this will panic.

pub unsafe fn unwrap_unchecked(self) -> usize

Return the success-value unchecked

Safety

This does not verify that self is actually a success-return. It assumes the caller verified it.

pub fn unwrap(self) -> usize

Return the success value

If self is not a success-return, this will panic.

pub fn to_result(self) -> Result<usize, usize>

Convert into a Result

This converts the return value into a rust-native Result type. This maps the error-return to Err(code) and the success-return to Ok(usize). This allows using the rich convenience library of the Result type, rather than re-implementing them for this native type.

Trait Implementations

impl Clone for Retval

fn clone(&self) -> Retval

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Retval

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

Formats the value using the given formatter.

impl PartialEq for Retval

fn eq(&self, other: &Retval) -> 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 Retval

impl Eq for Retval

impl StructuralPartialEq for Retval