smart_config::fallback

Trait FallbackSource

Source 
pub trait FallbackSource:
    'static
    + Send
    + Sync
    + Debug
    + Display {
    // Required method
    fn provide_value(&self) -> Option<WithOrigin>;
}
Expand description

Fallback source of a configuration param.

Required Methods§

Source

fn provide_value(&self) -> Option<WithOrigin>

Potentially provides a value for the param.

Implementations should return None (vs Some(Value::Null) etc.) if the source doesn’t have a value.

Implementors§