autodefault

A library that automatically inserts ..Default::default() for you.

The pitch

Has this ever happened to you?

```rust

[derive(Debug, Default, PartialEq, Eq)]

struct Inner { x: i32, y: i32, z: i32, }

[derive(Debug, Default, PartialEq, Eq)]

struct Mid { a: Inner, b: Inner, c: Inner, d: Inner }

[derive(Debug, Default, PartialEq, Eq)]

struct Outer { mid1: Mid, mid2: Mid, mid3: Mid, mid4: Mid, }

fn build_outer() -> Outer { Outer { mid1: Mid { a: Inner { x: 10, ..Default::default() // :D }, b: Inner { y: 10, ..Default::default() // :) }, ..Default::default() // :| }, mid2: Mid { b: Inner { z: 10, ..Default::default() // :/ }, ..Default::default() // :( }, ..Default::default() // >:( } } ```

Wouldn't it be nice if you could omit all the tedious ..Default::default() calls when building deeply nested struct literals? Now you can! With autodefault, it's never been easier to build up a large struct literal for your tests, bevy components, or anything else you might need!. Simply tag any function with the #[autodefault] attribute and let us handle the rest:

```rust use autodefault::autodefault;

[autodefault]

fn buildoutersimple() -> Outer { Outer { mid1: Mid { a: Inner { x: 10 }, b: Inner { y: 10 }, }, mid2: Mid { b: Inner { z: 10 }, } } } // :O

asserteq!(buildouter(), buildoutersimple()) ```

It's never been easier!

What it's actually doing

When applied to a function, the #[autodefault] will scan the body of the function for all struct literals that don't already have a ..rest trailing initializer and insert a ..Default::default(). It will do this unconditionally for all struct literals, regardless of whether they actually implement [Default], so be sure to refactor into helper functions as necessary:

```rust use autodefault::autodefault;

struct NoDefault { x: i32, y: i32, z: i32, }

// This will fail to compile

[autodefault]

fn nope() { let _nope = NoDefault { x: 10 }; } ```