Trait ContextExt 

pub trait ContextExt<T> {
    // Required methods
    fn context(
        self,
        message: impl Into<Cow<'static, str>>,
    ) -> Result<T, TestError>;
    fn with_context<F, S>(self, f: F) -> Result<T, TestError>
       where F: FnOnce() -> S,
             S: Into<Cow<'static, str>>;
}

Attaches context to the failure path of a Result or the None of an Option.

Required Methods

fn context(self, message: impl Into<Cow<'static, str>>) -> Result<T, TestError>

Adds a context frame describing the operation that was being attempted.

On the success path the value is returned unchanged.

fn with_context<F, S>(self, f: F) -> Result<T, TestError>

where F: FnOnce() -> S, S: Into<Cow<'static, str>>,

Like context, but the message is computed by f, which runs only on the failure path.

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> ContextExt<T> for Option<T>

fn context(self, message: impl Into<Cow<'static, str>>) -> Result<T, TestError>

fn with_context<F, S>(self, f: F) -> Result<T, TestError>

where F: FnOnce() -> S, S: Into<Cow<'static, str>>,

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

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

fn context(self, message: impl Into<Cow<'static, str>>) -> Result<T, TestError>

fn with_context<F, S>(self, f: F) -> Result<T, TestError>

where F: FnOnce() -> S, S: Into<Cow<'static, str>>,

Implementors