Trait Context 

pub trait Context {
    // Required method
    fn get(&self, key: &str) -> Option<String>;
}

A trait for providing values for variable expansion.

This allows format_with to be generic over the source of the variables, making it easy to test with a HashMap or use with environment variables.

Required Methods

fn get(&self, key: &str) -> Option<String>

Retrieves a value for a given key.

Parameters

• key: The name of the variable to look up.

Returns

• Some(String) if the key exists.
• None if the key does not exist.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<K, S> Context for HashMap<K, S>

where K: Borrow<str> + Eq + Hash, S: AsRef<str>,

fn get(&self, key: &str) -> Option<String>

Implementors