Attribute Macro corresponding_macros::derive_corresponding

#[derive_corresponding]

Use this macro on a module to generate MoveCorresponding implementations for all structs in this module. For all structs deriving Default also the From trait will be implemented.

Example

use corresponding::derive_corresponding;

#[derive_corresponding]
mod my_mod {
    #[derive(Debug, Default)]
    pub struct A {
        pub a: u8,
        pub b: u8,
        pub c: u8,
    }

    #[derive(Debug, Clone)]
    pub struct B {
        pub a: u8,
        pub b: Option<u8>,
        pub d: u8,
    }
}

This will implement MoveCorresponding for all combinations of structs within the crate module. The generated implementations are zero cost abstractions and will look like:

impl MoveCorresponding<B> for A {
    fn move_corresponding(&mut self, rhs: B) {
        self.a = rhs.a;
        if let Some(r) = rhs.b {
            self.b = r;
        }
    }
}

impl MoveCorresponding<A> for B {
    fn move_corresponding(&mut self, rhs: A) {
        self.a = rhs.a;
        self.b = Some(rhs.b);
    }
}

Because struct A derives Default, it will also implement From. The generated implementation looks like:

impl From<B> for A {
    fn from(rhs: B) -> Self {
        let mut lhs = A::default();
        lhs.move_corresponding(rhs);
        lhs
    }
}