rig-derive 0.43.0

Internal crate that implements Rig derive macros.
Documentation 
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use proc_macro2::TokenStream;
use syn::{Attribute, DataStruct, Meta, parse_quote};

use super::{EMBED, field_member};

/// Finds and returns fields with simple `#[embed]` attribute tags only.
pub(crate) fn basic_embed_fields(
    data_struct: &DataStruct,
) -> impl Iterator<Item = (syn::Member, &syn::Field)> {
    data_struct
        .fields
        .iter()
        .enumerate()
        .filter(|(_, field)| {
            field.attrs.iter().any(|attribute| match attribute {
                Attribute {
                    meta: Meta::Path(path),
                    ..
                } => path.is_ident(EMBED),
                _ => false,
            })
        })
        .map(|(index, field)| (field_member(index, field), field))
}

/// Adds bounds to where clause that force all fields tagged with `#[embed]` to implement the `Embed` trait.
pub(crate) fn add_struct_bounds(
    generics: &mut syn::Generics,
    field_type: &syn::Type,
    embed_trait: &TokenStream,
) {
    let where_clause = generics.make_where_clause();

    where_clause.predicates.push(parse_quote! {
        #field_type: #embed_trait
    });
}