-

macro_rules! deser {
    ($name:ident, $expect:expr, |$s:ident| $pred:expr) => {
        fn $name<'de, D: ::serde::Deserializer<'de>>(de: D) -> StdResult<bool, D::Error> {
            struct Visitor;

            impl<'de> ::serde::de::Visitor<'de> for Visitor {
                type Value = bool;

                fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
                    fmt.write_str($expect)
                }

                fn visit_str<E: ::serde::de::Error>(self, $s: &str) -> StdResult<bool, E> {
                    Ok($pred)
                }
            }

            de.deserialize_str(Visitor)
        }
    }
}

deser!(check_to_bool, "an empty string or a check mark ✓", |s| !s.is_empty());
deser!(yesno_to_bool, "Yes or No", |s| s == "Yes");