Optifier

Proc macro crate: Partial derive

[!note] This crate is early development phase. I use it only in my personal projects and update it as needed.

Derive Partial on a struct Foo to generate a new struct named FooPartial where every field type is wrapped in Option<T> unless it is already an Option<T>. Only structs with named fields are accepted; tuple and unit structs are not supported yet.

Example:

use optifier;

#[derive(optifier::Partial)]
#[optifier::partial_derive(Debug, Clone)]
pub struct Foo {
    a: i32,
    b: Option<String>,
    pub c: Vec<u8>,
}

expands to:

#[derive(Debug, Clone)]
pub struct FooPartial {
    a: Option<i32>,
    b: Option<String>, // stays as-is
    pub c: Option<Vec<u8>>,
}

#[optifier::partial_derive(...)] attribute

The #[optifier::partial_derive(...)] attribute configures which traits are derived for the generated *Partial type.

• It is applied to the original struct, together with #[derive(optifier::Partial)].
• It accepts a comma-separated list of trait paths (e.g. Debug, Clone, PartialEq, or fully qualified paths).
• Whatever traits you list there are emitted as a #[derive(...)] on the generated <OriginalName>Partial type.

Example:

use optifier;

#[derive(optifier::Partial)]
#[optifier::partial_derive(Debug, Clone, PartialEq)]
pub struct Foo {
    a: i32,
    b: Option<String>,
}

generates roughly:

#[derive(Debug, Clone, PartialEq)]
pub struct FooPartial {
    a: Option<i32>,
    b: Option<String>,
}