Trait ErrorContext

pub trait ErrorContext: SealedErrorContext {
    type Context;

    // Required methods
    fn context<M>(self, context: M) -> Self::Context
       where M: Display + Send + Sync + 'static;
    fn with_context<C, F>(self, context: F) -> Self::Context
       where C: Display + Send + Sync + 'static,
             F: FnOnce() -> C;
}

Extends the Result and Option types with methods for adding context to errors.

See the module level documentation for more information.

Examples

use rama_error::ErrorContext;

let result = "hello".parse::<i32>().context("parse integer");
assert_eq!("parse integer\r\n ↪ invalid digit found in string", result.unwrap_err().to_string());

Required Associated Types

type Context

The resulting contexct type after adding context to the contained error.

Required Methods

fn context<M>(self, context: M) -> Self::Context

where M: Display + Send + Sync + 'static,

Add a static context to the contained error.

fn with_context<C, F>(self, context: F) -> Self::Context

where C: Display + Send + Sync + 'static, F: FnOnce() -> C,

Lazily add a context to the contained error, if it exists.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T> ErrorContext for Option<T>

type Context = Result<T, OpaqueError>

fn context<M>(self, context: M) -> <Option<T> as ErrorContext>::Context

where M: Display + Send + Sync + 'static,

fn with_context<C, F>(self, context: F) -> <Option<T> as ErrorContext>::Context

where C: Display + Send + Sync + 'static, F: FnOnce() -> C,

impl<T, E> ErrorContext for Result<T, E>

where E: Error + Send + Sync + 'static,

type Context = Result<T, OpaqueError>

fn context<M>(self, context: M) -> <Result<T, E> as ErrorContext>::Context

where M: Display + Send + Sync + 'static,

fn with_context<C, F>( self, context: F, ) -> <Result<T, E> as ErrorContext>::Context

where C: Display + Send + Sync + 'static, F: FnOnce() -> C,

Implementors