darling_core/from_attributes.rs
use syn::Attribute;
use crate::Result;
/// Create an instance by parsing a list of attributes.
///
/// This trait is useful when dealing with items such as traits on traits and impl blocks,
/// for which `darling` does not provide dedicated traits.
pub trait FromAttributes: Sized {
/// Create an instance by parsing a list of attributes.
///
/// By convention, `FromAttributes` implementations should merge item
/// declarations across attributes, so that the following forms are
/// equivalent:
///
/// ```rust,ignore
/// #[derive(Serialize)]
/// #[serde(rename_all = "camel_case")]
/// #[serde(borrow)]
/// pub struct SplitExample {}
///
/// #[derive(Serialize)]
/// #[serde(borrow, rename_all = "camel_case")]
/// pub struct JoinedExample {}
/// ```
fn from_attributes(attrs: &[Attribute]) -> Result<Self>;
}