Function parse_or

pub fn parse_or<T>(
    key: &str,
    expected: &'static str,
    default: T,
) -> Result<T, EnvError>where
    T: FromStr,

Expand description

Reads and parses a variable, falling back to default when absent.

§Errors

EnvError::Invalid if present but malformed — substituting the default for a typo is how a server ends up listening on the wrong port.