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Last update: 29/03/2026

enum-as-inner

Macros for deriving as functions to access Enums as their inner components

Latest version: 0.7.0 registry icon
Maintenance score
46
Safety score
100
Popularity score
73
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Security
  Vulnerabilities
Version Suggest Low Medium High Critical
0.7.0 0 0 0 0 0
0.6.1 0 0 0 0 0
0.6.0 0 0 0 0 0
0.5.2 0 0 0 0 0
0.5.1 0 0 0 0 0
0.5.0 0 0 0 0 0
0.4.0 0 0 0 0 0
0.3.4 0 0 0 0 0
0.3.3 0 0 0 0 0
0.3.2 0 0 0 0 0
0.3.1 0 0 0 0 0
0.3.0 0 0 0 0 0
0.2.1 0 0 0 0 0
0.2.0 0 0 0 0 0
0.1.0 0 0 0 0 0

Stability
Latest release:

0.7.0 - This version may not be safe as it has not been updated for a long time. Find out if your coding project uses this component and get notified of any reported security vulnerabilities with Meterian-X Open Source Security Platform

Licensing

Maintain your licence declarations and avoid unwanted licences to protect your IP the way you intended.

Apache-2.0   -   Apache License 2.0

Not a wildcard

Not proprietary

OSI Compliant

MIT   -   MIT License

Not a wildcard

Not proprietary

OSI Compliant

enum-as-inner

A deriving proc-macro for generating functions to automatically give access to the inner members of enum.

Basic unnamed field case

The basic case is meant for single item enums, like:

use enum_as_inner::EnumAsInner;

#[derive(Debug, EnumAsInner)]
enum OneEnum {
    One(u32),
}

where the inner item can be retrieved with the as_*()/as_*_mut(), into_*() or with the *unchecked functions:

let one = OneEnum::One(1);

assert_eq!(*one.as_one().unwrap(), 1);
assert_eq!(one.into_one().unwrap(), 1);

let mut one = OneEnum::One(2);

assert_eq!(*one.as_one().unwrap(), 1);
assert_eq!(*one.as_one_mut().unwrap(), 1);
assert_eq!(one.into_one().unwrap(), 1);

unsafe {
    assert_eq!(*one.as_one_unchecked(), 1);
    assert_eq!(*one.as_one_mut_unchecked(), 1);
    assert_eq!(one.into_one_unchecked(), 1);
}

where the result is either a reference for inner items or a tuple containing the inner items. The *unchecked functions are unsafe and return either a reference or a tuple containing the inner items.

Unit case

This will return true if enum's variant matches the expected type

use enum_as_inner::EnumAsInner;

#[derive(EnumAsInner)]
enum UnitVariants {
    Zero,
    One,
    Two,
}

let unit = UnitVariants::Two;

assert!(unit.is_two());

Mutliple, unnamed field case

This will return a tuple of the inner types:

use enum_as_inner::EnumAsInner;

#[derive(Debug, EnumAsInner)]
enum ManyVariants {
    One(u32),
    Two(u32, i32),
    Three(bool, u32, i64),
}

And can be accessed like:

let mut many = ManyVariants::Three(true, 1, 2);

assert_eq!(many.as_three().unwrap(), (&true, &1_u32, &2_i64));
assert_eq!(many.as_three_mut().unwrap(), (&mut true, &mut 1_u32, &mut 2_i64));
assert_eq!(many.into_three().unwrap(), (true, 1_u32, 2_i64));

unsafe {
    assert_eq!(many.as_three_unchecked(), (&true, &1_u32, &2_i64));
    assert_eq!(many.as_three_mut_unchecked(), (&mut true, &mut 1_u32, &mut 2_i64));
    assert_eq!(many.into_three_unchecked(), (true, 1_u32, 2_i64));
}

Multiple, named field case

This will return a tuple of the inner types, like the unnamed option:

use enum_as_inner::EnumAsInner;

#[derive(Debug, EnumAsInner)]
enum ManyVariants {
    One{ one: u32 },
    Two{ one: u32, two: i32 },
    Three{ one: bool, two: u32, three: i64 },
}

And can be accessed like:

let mut many = ManyVariants::Three{ one: true, two: 1, three: 2 };

assert_eq!(many.as_three().unwrap(), (&true, &1_u32, &2_i64));
assert_eq!(many.as_three_mut().unwrap(), (&mut true, &mut 1_u32, &mut 2_i64));
assert_eq!(many.into_three().unwrap(), (true, 1_u32, 2_i64));

unsafe {
    assert_eq!(many.as_three_unchecked(), (&true, &1_u32, &2_i64));
    assert_eq!(many.as_three_mut_unchecked(), (&mut true, &mut 1_u32, &mut 2_i64));
    assert_eq!(many.into_three_unchecked(), (true, 1_u32, 2_i64));
}