Impl From Macro

The implementation of trait From.

See more macros: docs, repository.

Examples:

Struct

#[derive(From, Debug, PartialEq)]
#[from(&str, expr = value.to_string().into())]
pub struct Email(String);

assert_eq!(
    Email::from("user@example.com".to_string()),
    "user@example.com".into()
);

Enum

#[derive(From, Debug, PartialEq)]
pub enum Value {
    Integer(i32),

    #[from(skip)]
    Integer2(i32),

    Float(f64),

    #[from((), expr = Self::Null)]
    Null,

    #[from(&str, with = String::from)]
    String(String),
}

assert_eq!(Value::Integer(42), 42.into());
assert_eq!(Value::Float(3.14), 3.14.into());
assert_eq!(Value::Null, ().into());
assert_eq!(Value::String("test".to_string()), "test".into());

License & Feedback:

This library distributed under the MIT license.

You can contact me via GitHub or send a message to my E-Mail. This library is actively evolving, and your suggestions and feedback are always welcome!