Created
January 17, 2017 15:30
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Rust enum with str representation
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macro_rules! enum_with_str_representation { | |
(enum $enum_name:ident { | |
$($variant:ident => $nice_name:expr,)+ | |
}) => { | |
#[derive(Debug, PartialEq, Eq, Clone, Hash)] | |
enum $enum_name { | |
$($variant),+ | |
} | |
impl ::std::fmt::Display for $enum_name { | |
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result { | |
match *self { | |
$($enum_name::$variant => write!(f, $nice_name)),+ | |
} | |
} | |
} | |
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] | |
struct ParseError; | |
impl ::std::str::FromStr for $enum_name { | |
type Err = ParseError; | |
fn from_str(s: &str) -> Result<$enum_name, Self::Err> { | |
match s { | |
$($nice_name => Ok($enum_name::$variant),)+ | |
_ => Err(ParseError), | |
} | |
} | |
} | |
} | |
} | |
enum_with_str_representation! { | |
enum Status { | |
Success => "Success", | |
NoContent => "No content", | |
NotFound => "Not found", | |
} | |
} | |
fn main() { | |
println!("{:?}", Status::Success); | |
println!("{:?}", "Not found".parse::<Status>()); | |
println!("{:?}", "Internal Server Error".parse::<Status>()); | |
println!("{:?}", "Internal Server Error".parse::<Status>()); | |
} |
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