structural-convert

Derive conversion traits when items are structurally similar.

Inspired by serde and struct-convert crates.

Features

• One to one fields mapping derive for
  • From
  • Into
  • TryFrom
  • TryInto
• Inner fields type conversion using .into()/.try_into()
• Rename enum variants and named fields
• Skip enum variants and named fields
• Fallback to default enum variant
• Named fields conversion fallback to default
• Enum not matched variants fallback to enum default
• Struct named fields only - Middle man type conversion using as attribute

Features Wishlist

• Stop relying on panic and unwrap and use proper errors with spans

Examples

Check the tests folder for more examples, but here is some samples:

Struct

#[derive(Debug, PartialEq)]
struct Rhs {
    z: i8,
    x: u32,
}

#[derive(Debug, PartialEq, StructuralConvert)]
#[convert(from(path = "Rhs"))]
struct Lhs {
    z: i32,
    x: u32,
}

assert_eq!(Lhs { z: 1, x: 2 }, Rhs { z: 1, x: 2 }.into());
assert_eq!(Lhs { z: 1, x: 2 }, Rhs { z: 1, x: 2 }.into());

Generated code:

impl From<Rhs> for Lhs {
    fn from(value: Rhs) -> Self {
        match value {
            Rhs { z, x } => Lhs {
                z: z.into(),
                x: x.into(),
            },
        }
    }
}

Enum

    #[derive(Debug, PartialEq)]
    enum Rhs {
        A { z: i8, x: u32 },
    }

    #[derive(Debug, PartialEq, StructuralConvert)]
    #[convert(from(path = "Rhs"))]
    enum Lhs {
        A { z: i32, x: u32 },
    }

    assert_eq!(Lhs::A { z: 1, x: 2 }, Rhs::A { z: 1, x: 2 }.into());

Generated code:

impl From<Rhs> for Lhs {
    fn from(value: Rhs) -> Self {
        match value {
            Rhs::A { z, x } => Lhs::A {
                z: z.into(),
                x: x.into(),
            },
        }
    }
}