Struct Context 

pub struct Context { /* private fields */ }

A context for error handling, when interacting directly with the generated bindings for the C API in [nix_bindings_util_sys].

The nix-store and nix-expr libraries that consume this type internally store a private context in their EvalState and Store structs to avoid allocating a new context for each operation. The state of a context is irrelevant when used correctly (e.g. with check_call!), so it’s safe to reuse, and safe to allocate more contexts in methods such as Clone::clone.

Implementations

impl Context

pub fn new() -> Self

pub fn ptr(&mut self) -> *mut c_context

Access the C context pointer.

We recommend to use check_call! if possible.

pub fn check_err(&self) -> Result<()>

Check the error code and return an error if it’s not NIX_OK.

We recommend to use check_call! if possible.

pub fn clear(&mut self)

pub fn check_err_and_clear(&mut self) -> Result<()>

pub fn check_one_call_or_key_none<T, F: FnOnce(*mut c_context) -> T>( &mut self, f: F, ) -> Result<Option<T>>

Trait Implementations

impl Default for Context

fn default() -> Self

Returns the “default value” for a type.

impl Drop for Context

fn drop(&mut self)

Executes the destructor for this type.