bert/
enum_macro.rs

1// Special wrapper around the enum type, which provide an opportunity to
2// serialize/deserialize enum variants as a string
3
4
5#[macro_export]
6macro_rules! enum_str {
7    ($name:ident { $($variant:ident($str:expr), )* }) => {
8        #[derive(Clone, Copy, Debug, Eq, PartialEq)]
9        pub enum $name {
10            $($variant,)*
11        }
12
13        impl ::serde::Serialize for $name {
14            fn serialize<S>(&self, serializer: S) -> ::std::result::Result<S::Ok, S::Error>
15                where S: ::serde::Serializer,
16            {
17                serializer.serialize_str(match *self {
18                    $( $name::$variant => $str, )*
19                })
20            }
21        }
22
23        impl<'de> ::serde::Deserialize<'de> for $name {
24            fn deserialize<D>(deserializer: D) -> ::std::result::Result<Self, D::Error>
25                where D: ::serde::Deserializer<'de>,
26            {
27                struct EnumVisitor;
28
29                impl<'de> ::serde::de::Visitor<'de> for EnumVisitor {
30                    type Value = $name;
31
32                    fn expecting(&self, formatter: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
33                        formatter.write_str(concat!("a string matching one of the ", stringify!($name), " variants"))
34                    }
35
36                    fn visit_str<E>(self, value: &str) -> ::std::result::Result<$name, E>
37                        where E: ::serde::de::Error,
38                    {
39                        match value {
40                            $( $str => Ok($name::$variant), )*
41                            _ => Err(E::custom(format!("unknown {} variant: {}", stringify!($name), value))),
42                        }
43                    }
44                }
45
46                deserializer.deserialize_str(EnumVisitor)
47            }
48        }
49    }
50}
bert/enum_macro.rs

bert/
enum_macro.rs
