Trait MapErrWithSpan

pub(crate) trait MapErrWithSpan<E, E2>: Sized {
    type Output: Sized;

    // Required method
    fn map_err_inner<F, E3>(self, func: F) -> Self::Output
       where F: FnOnce(E) -> WithSpan<E3>,
             E2: From<E3>;
}

Convenience trait for Result, adding a MapErrWithSpan::map_err_inner mapping to WithSpan::and_then.

Required Associated Types

type Output: Sized

The returned output type.

Required Methods

fn map_err_inner<F, E3>(self, func: F) -> Self::Output

where F: FnOnce(E) -> WithSpan<E3>, E2: From<E3>,

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, E, E2> MapErrWithSpan<E, E2> for Result<T, WithSpan<E>>

type Output = Result<T, WithSpan<E2>>

fn map_err_inner<F, E3>(self, func: F) -> Result<T, WithSpan<E2>>

where F: FnOnce(E) -> WithSpan<E3>, E2: From<E3>,

Implementors