#traits #unit-testing #testing #impl-block #proc-macro #generate #derive

nightly macro trait_derive

Simple proc macro used to generate traits from impl blocks

1 unstable release

Uses old Rust 2015

0.1.0 Dec 1, 2017

#25 in #impl-block

MIT license

15KB
173 lines

trait_derive is a small crate that will generate a trait based on the impl blocks of your structs. This will save repitition in cases where you want to generate a trait for testing purposes, or you want to turn exsisting code into a trait for decoupling purposes.

To add it to your project, add the following line to your Cargo.toml

trait_derive = "0.1.0"

Currently, trait_derive requires you to be running nightly Rust. This will hopefully change in the future, once proc macros are stable.

Examples

Using this crate looks something like this:

#![feature(proc_macro)]
extern crate trait_derive;

use trait_derive::make_trait;

pub struct A;

#[make_trait] // This will generate a trait named 'TraitA' by default.
impl A {
    pub fn hello_world(&self) {
        println!("Hello, world!");
    }
}

fn takes_trait(x: &TraitA) {
   x.hello_world();
}
    
fn basic_usage() {
   let a = A { };
   takes_trait(&a);
}

#[make_trait(Database)] // This will generate a trait named 'Database'
impl A {
    pub fn query(&self) -> u32 {
        32
    }
}

Dependencies

~2MB
~42K SLoC