Derive macros for the prefer configuration library.

This crate provides the #[derive(FromValue)] macro for automatically implementing the FromValue trait on structs and enums.

Example

use prefer::FromValue;
use prefer_derive::FromValue;

#[derive(FromValue)]
struct ServerConfig {
    host: String,
    port: u16,
    #[prefer(default = "false")]
    debug: bool,
}