Function builder 

pub fn builder<T>() -> Result<ConfigBuilder<T>, BuilderError>
where
    T: Facet<'static>,

Start configuring an args/config parser for a given type.

This is the main entry point for building layered configuration. The type T must implement Facet and be properly annotated with figue attributes.

Example

use facet::Facet;
use figue::{self as args, builder, Driver};

#[derive(Facet)]
struct Args {
    #[facet(args::named, default)]
    verbose: bool,
    #[facet(args::positional)]
    file: String,
}

let config = builder::<Args>()
    .expect("schema should be valid")
    .cli(|cli| cli.args(["--verbose", "input.txt"]))
    .build();

let args: Args = Driver::new(config).run().unwrap();
assert!(args.verbose);

Errors

Errors

Returns an error if:

• The type is not a struct (enums cannot be root types)
• Fields are missing required annotations (args::positional, args::named, etc.)
• Schema validation fails