Method convert

option_parser/src/lib.rs:275–288

Retrieves and converts an option value to type `T`. Returns `Ok(None)` if the option was not set or its value is empty. Returns `Err` if the value cannot be converted to `T`. `T` can be any type that implements `FromStr` (e.g. `u32`, `String`), or one of this crate's types such as [`Toggle`], [`IntegerList`], [`Tuple`], or [`StringList`].

(&self, option: &str)

    /// or one of this crate's types such as [`Toggle`], [`IntegerList`],
    /// [`Tuple`], or [`StringList`].
    pub fn convert<T: Parseable>(&self, option: &str) -> OptionParserResult<Option<T>> {
        match self.options.get(option).and_then(|v| v.value.as_ref()) {
            None => Ok(None),
            Some(v) => {
                Ok(if v.is_empty() {
                    None
                } else {
                    Some(Parseable::from_str(v).map_err(|_| {
                        OptionParserError::Conversion(option.to_owned(), v.to_owned())
                    })?)
                })
            }
        }
    }
}

/// A boolean-like value that accepts `"on"`, `"true"`, `"off"`, `"false"`, or `""`.