Function derive

impl/src/expand.rs:12–20

(input: &DeriveInput)

use syn::{DeriveInput, GenericArgument, PathArguments, Result, Token, Type};

pub fn derive(input: &DeriveInput) -> TokenStream {
    match try_expand(input) {
        Ok(expanded) => expanded,
        // If there are invalid attributes in the input, expand to an Error impl
        // anyway to minimize spurious secondary errors in other code that uses
        // this type as an Error.
        Err(error) => fallback::expand(input, error),
    }
}

fn try_expand(input: &DeriveInput) -> Result<TokenStream> {
    let input = Input::from_syn(input)?;