request_value in core::error - Rust
Description: Requests a value of type `T` from the given `impl Error`.

## request_value

# Function request_value

Source

    pub fn request_value<'a, T>(err: &'a (impl Error + ?Sized)) -> Option<T>where
        T: 'static,

🔬This is a nightly-only experimental API. (`error_generic_member_access` #99301)
Expand description

Requests a value of type `T` from the given `impl Error`.

## §Examples

Get a string value from an error.

    #![feature(error_generic_member_access)]
    use std::error::Error;
    use core::error::request_value;

    fn get_string(err: &impl Error) -> String {
        request_value::<String>(err).unwrap()
    }